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. 2026 Jan 23;4(6):957–969. doi: 10.1021/cbmi.5c00232

Fluorescent J‑Aggregates in the NIR-II Window: Unlocking Frontiers in Biomedical Imaging

Xing Wei 1, Wei Chen 1,*
PMCID: PMC13291981  PMID: 42358780

Abstract

Fluorescent organic dyes have long served as versatile scaffolds for developing multifunctional imaging tools in biomedicine. The pursuit of fluorophores in the second near-infrared window (NIR-II) represents a major Frontier, aiming to deepen our view into living systems. Current paradigms, predominantly focused on extending π-conjugation, are frequently hampered by synthetic complexity and aggregation-caused quenching (ACQ), creating a barrier to clinical translation. In this perspective, we contend that J-aggregation offers a promising and alternative strategy: a more facile and spectrally tunable route to high-performance NIR-II emission. We analyze the design principles regulating J-aggregate formation across diverse molecular scaffolds, from cyanines and boron-dipyrromethene (BODIPY) derivatives to emerging fluorophore scaffolds, and synthesize their recent applications in bioimaging, biosensing, and theranostics. We also discuss the key challenges of current NIR-II emissive J-aggregates (e.g., low fluorescence quantum yield, poor in vivo stability) in biomedical applications, alongside prospects for advancing their development toward routine use in biomedicine.

Keywords: J-aggregates, fluorophores, NIR-II imaging, fluorescence, surgical navigation, clinical translation

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1. Introduction

Near-infrared-II (NIR-II) organic dyes, capitalizing on the distinctive merits of NIR-II light (1000–1700 nm) such as minimal tissue scattering, low autofluorescence, and deep penetration depth, have emerged as transformative tools in advanced bioimaging, enabling high-resolution visualization of biological processes and precise disease diagnostics in vivo. − Currently, the NIR-II emission of existing organic dyes is predominantly achieved through molecular engineering strategies, including constructing extended π-conjugation systems, modifying molecular structures by heteroatom substitution, and incorporating strong electron donors (D) and electron acceptors (A) to redshift emission wavelengths. − However, achieving efficient NIR-II emission remains challenging due to the scarcity of optimal π-conjugation frameworks that balance emission performance with stability and biocompatibility. − To date, most NIR-II dyes are derived from classic scaffolds such as polymethines, boron-dipyrromethene (BODIPY) dyes, and rhodamine analogues, limiting structural diversity and functional expansion. Against this backdrop, exploring alternative approaches to develop high-performance NIR-II dyes is increasingly imperative. ,,−

A promising complementary strategy lies in the creation of NIR-II fluorescent J-aggregates. J-aggregates are supramolecular assemblies formed by highly ordered, slipped-stacked arrangements of organic chromophores. Compared to their monomeric counterparts, they exhibit unique optical properties, including narrow and red-shifted absorption and emission bands, enhanced molar extinction coefficients (MEC), and improved photostabilityfeatures that are highly desirable for NIR-II bioimaging. ,,, These distinctive properties stem primarily from strong excitonic coupling, a phenomenon enabled by the highly ordered “head-to-tail” molecular packing within the supramolecular assembly. The ordered supramolecular structure of J-aggregates not only optimizes their optical performance but also confers excellent adaptability in biological applications, such as vascular imaging, tumor visualization, surgical navigation, and synergistic phototherapy, thereby opening innovative avenues for advancing medical diagnosis and treatment. −

Despite significant progress in the development of NIR-II fluorescent J-aggregates, their design remains largely empirical, lacking systematic strategies and predictable ruleskey challenges that hinder the rational optimization of probes for diverse biological scenarios. Unlike prior excellent reviews that systematically categorize the molecular design strategies and scaffold diversity of NIR-II J-aggregates, this perspective provides a distinct, complementary, application-oriented critique aimed at accelerating translational progress. We focus on the latest advancements in NIR-II organic J-aggregates (Figure ), with a particular emphasis not only on their design principles (including molecular engineering of building blocks and supramolecular assembly regulation) and their applications in bioimaging, biosensing, and therapeutic modalities, but also on the translational bottlenecks that connect these domains. We also analyze the core advantages (e.g., enhanced optical performance, structural tunability) and inherent limitations (e.g., assembly instability, poor reproducibility) of these aggregates. Finally, we discuss the remaining hurdles (e.g., precise control over assembly in complex biological environments) and potential opportunities (e.g., integration with multimodal imaging) in advancing NIR-II J-aggregates. Our aim is to shift the research focus from “how to design” to “how to translate”, providing valuable insights for the development of high-performance systems and accelerate their translation into biomedical practice.

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Representative molecules with J-aggregation induced the NIR-II fluorescence.

2. Cyanine-Based J-Aggregates

Currently, cyanine-based NIR J-aggregate fluorophores have emerged as the core research objects for NIR-II bioimaging. ,− Research teams have driven breakthroughs in their applications in scenarios such as deep-tissue imaging and theranostics via strategies of self-assembly regulation, molecular structure modification, and functional response design. Nevertheless, common technical bottlenecks persist. Below, combined with representative achievements, the current status of the field and unresolved issues is summarized.

2.1. Self-Assembly Regulation: Achieving Performance Optimization of J-Aggregates via Carrier/Interface Interactions

Regulating the self-assembly behavior of cyanine fluorophores to construct stable J-aggregates suitable for NIR-II imaging was the core strategy in early research, among which nanocarrier assistance and amphiphilic molecule self-assembly are two typical approaches.

The 2019 work by Sletten et al. pioneered a strategy for the controlled assembly of IR-140 J-aggregates in hollow mesoporous silica nanoparticles (HMSNs) via charge-based association that simultaneously enhanced both the structural integrity and photostability of the aggregates, enabling their application in NIR-II imaging (Figure a–c). The negatively charged silica surface guides the assembly of cationic dyes through electrostatic interactions, promoting slip-stacked J-aggregation. However, we contend that mere stability is insufficient for clinical translation. Critically low quantum yields impaired sensitivity, while unvalidated theranostic claims highlighted a broader field-wide challenge: moving from imaging probes to functionally integrated systems. Future designs should couple assembly control with rigorous therapeutic validation to bridge this gap.

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(a) Structure of IR-140 and preparing for IR-140 J-aggregates. (b) Spectral characteristics and photostability of IR-140 monomer, J-aggregates in solution or in HMSNs-PEG. (c) Whole-mouse imaging upon i.v. delivery of IR-140 HMSNs-PEG (excitation: 980 nm; collection: 1000–1700 nm). Reproduced from ref . Copyright 2019 American Chemical Society. (d) Structures of FD-1080 and DMPC. (e) Normalized spectral characteristics of FD-1080 monomer and J-aggregates. (f) Fluorescence images of brain and hindlimb vessels obtained using J-aggregates in different regions. (g) Dynamic bioimaging of carotid artery after Isoket administration that exceeds the 1500 nm window, achieved using J-aggregates. Reproduced from ref . Copyright 2019 American Chemical Society. (h) J-aggregate formation mechanism in mesoporous channels. (i) Absorption of FD-1080 and J-aggregate. (j) Schematic illustration of minimally invasive osteosynthesis guided by NIR-II imaging. (k) Fluorescence images of in vivo implanted MSTPs-FDJ@PAA. (l) 3D grayscale images of ROI 1 located in the yellow dotted box from (k). Reproduced with permission from ref . Copyright 2021 Wiley-VCH.

The Zhang group then focused on amphiphilic molecule self-assembly, inducing amphiphilic cyanine dye FD-1080 and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) to self-assemble into J-aggregates. Here, electrostatic interactions between the hydrophilic groups drive assembly, while steric and repulsive forces between the sulfonate heads of FD-1080 dictate a slipped-stack geometry, enabling J-aggregate formation. These aggregates show absorption at 1360 nm and emission at 1370 nm, enabling high-resolution NIR-II imaging of deep vasculature and real-time monitoring of the blood vessel width change to noninvasively evaluate hypotensive drug efficacy (Figure d–g). We view this as a pivotal demonstration of how supramolecular design can achieve bathochromic shifts without extended conjugation. Building on this, the group further expanded the application by loading J-aggregates formed by FD-1080 and poly­(acrylic acid) (PAA) onto the surface of composite scaffolds consisting of titanium plate substrates with mesoporous silica coatings, constructing biocompatible NIR-II MSTPs-FDJ@PAA. With absorption/fluorescence over 1300 nm, the implants met high-resolution, real-time deep-tissue surgical navigation needs, localized accurately in vitro/in vivo (Figure h–l), and improved bone fixation surgeries.

2.2. Molecular Structure Modification: Regulating J-Aggregates via Chemical Design

To overcome the limitations of external condition-dependent self-assembly, research has shifted toward intrinsic molecular structure modification of cyanine dyes. By altering the chemical backbone, precise control over the spectral and functional properties of J-aggregates can be achieved.

Zhao et al. developed a series of NIR-II J-aggregates from heptamethine cyanines by incorporating a bulky meso-substituent with trifluoroacetyl and benzyl groups, whose spectral properties were precisely tuned through minor modifications to the N-benzyl moiety. Bulky meso-substituents introduce steric hindrance to favor the formation of slip-stacked J-aggregates. To ensure aqueous stability for in vivo imaging, the J-aggregates of CYJ981 and CYJ1059 were encapsulated in Pluronic F127 micelles. For multiplexed three-color NIR-II fluorescence and multispectral optoacoustic tomography (MSOT) imaging, the encapsulated J-aggregates (CYJ981@F127 and CYJ1059@F127) were selected alongside a kidney-targeted monomeric probe 1@β-LG to achieve optimal spectral separation and minimize crosstalk (Figure a–c). A key finding from this study is that when the single crystal structure of a dye shows characteristics that align with J-aggregation, the dye may possess an inherent tendency to form J-aggregates. This establishes crystallographic analysis as a powerful tool for the rational design of J-aggregating cyanine dyes.

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(a) Structures of CYJ1059, CYJ981 and dye 1. (b) Normalized absorption spectra and fluorescence images of solutions containing the three dyes (1@β-LG at 13 μM, CYJ981@F127 at 11 μM, and CYJ1059@F127 at 6.5 μM); each solution was excited at 808, 980, or 1064 nm, and their emissions were collected using a 900, 1100, or 1200 nm long-pass filter, respectively. (c) Representative NIR-II/3D MSOT images of three dyes in vivo. Reproduced with permission from ref . Copyright 2024 Wiley-VCH. (d) Structure and (e) Absorption spectra of CyN-OMe in different solutions. (f) Photothermal imaging of tumor-bearing mice administered with Lipo@CyN-OMe. (g) Dissected tumors post-treatment with different samples. Reproduced from ref . Copyright 2025 American Chemical Society.

Alternatively, the Peng group modified a heptamethine cyanine (Cy7) dye by incorporating amethoxycarbonyl-substituted azaindole moiety. This led to the precise modulation of intramolecular electronic distribution and intermolecular interactions, which promoted the rapid formation of charge transfer-mediated CyN-OMe J-aggregates in saline solutions. The resulting J-aggregates exhibited a significant 160 nm bathochromic shift to 1035 nm, along with excellent photostability and biostability. Owing to their high photothermal conversion efficiency (63.7% under 1064 nm irradiation), the CyN-OMe J-aggregates enabled complete tumor ablation in vivo (Figure d–g). This work provides valuable insights into the creation of J-aggregates with ultralarge redshifts, which arises from a general design strategy that leverages precise control over intermolecular interactions.

2.3. Toward Intelligent Bioimaging: Responsive J-Aggregates as Activatable Molecular Probes

The development of responsive J-aggregates represents a pivotal shift toward intelligent bioimaging systems capable of molecular recognition and signal activation on demand. By incorporating specific recognition unit to biomarkers such as reactive oxygen species (ROS) or enzymes, these aggregates significantly enhance imaging specificity and diagnostic accuracy in the NIR-II region, opening avenues for precise pathological observation and timely intervention.

A typical example is the ONOO–-responsive IR-1061 J-aggregate (J IR‑1061) developed by the Liu group, which exhibits absorption at 1580 nm. By conjugating J IR‑1061 with rare earth nanoparticles (RENPs), a fluorescence/photoacoustic dual-modal probe, RENPs-J IR‑1061, was engineered. ONOO– enables RENPs-JIR-1061 to produce both intense photoacoustic signal changes and activatable fluorescence signals (Figure d,e), thus allowing real-time, high-contrast monitoring of hepatotoxicity in mice (Figure ). This platform offers a sensitive, noninvasive approach for preclinical monitoring of drug-induced liver injury while showing substantial potential to hepatotoxicity screening of novel drug candidates.

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(a) Design of dual-modal probe RENPs-J IR‑1061. (b) Schematic illustration for the preparation of J IR‑1061. (c) Normalized absorption and fluorescence spectra of IR-1061 and J IR‑1061. (d) Fluorescence spectra and (e) photoacoustic signal changes of RENPs-J IR‑1061 in the presence of of ONOO–. (f) MSOT images and (g) NIR-II fluorescence images of RENPs-J IR‑1061 in vivo. Reproduced from ref . Available under a CC BY-NC-ND 4.0 license. Copyright 2025 Wu, K.; et al.

Despite considerable progress in cyanine-based NIR J-aggregates, the transition from responsive J-aggregates to clinical applications faces several key challenges. Low fluorescence quantum yields (in systems like IR-140 and CyN-OMe) still limit detection sensitivity. Furthermore, while multifunctional designs such as “imaging-therapy” have been proposed (e.g., the HMSNs system), most lack thorough experimental validation and holistic integration. Practical barriers also remain, including complex formulation requirements and insufficient in vivo biosafety assessment. Addressing these issues through concerted materials innovation and rigorous biological evaluation will be essential to fully realize the potential of J-aggregates in precision medicine.

3. BODIPY-Derived J-Aggregates

BODIPY dyes have gained prominence as core materials in biomedical imaging and therapy due to their high photostability, tunable electronic properties, and good biocompatibility. Their J-aggregates exhibit bathochromic shifts, improved photostability, and unique photophysical behaviors, offering a promising alternative to conventional small-molecule dyes for applications requiring deep tissue penetration and multifunctional integration. Critically, when these dyes are strategically modified and stacked into J-aggregates, they often display enhanced brightness and can generate heat or ROS, thereby enabling integrated theranostics. Recent efforts have focused on modulating J-aggregate behavior through molecular design, yielding numerous innovative systems with potential practical utility − Nevertheless, critical challenges remain, particularly in balancing performance metrics and achieving clinical translation. This section highlights key advances in the field, examines persistent limitations, and discusses future directions for development.

3.1. Self-Assembly Regulation: Enhancing Stability and Biocompatibility via Nanocarrier Optimization

To improve the stability and biocompatibility of BODIPY J-aggregates, the Liu group employed a nanocarrier-assisted self-assembly strategy. By encapsulating a modified BODIPY dye PCP-BDP2 within Pluronic F127, they achieved stable J-aggregates with absorption at 750 nm and NIR-II emission at 1010 nm, along with a fluorescence quantum yield of 6.4%. The steric andconjugative effects of the [2,2]­paracyclophane (PCP) group attached to the BODIPY are critical in regulating both the J-aggregation behavior and the modulation of photophysical properties. The bulky PCP group sterically promotes slip-stacked ordering. This system enabled high-contrast, real-time imaging of lymph nodes and lymphatic vessels in nude mice and achieved fluorescence-guided lymphatic resection. The work thus provides a classic example of how carrier-stabilized J-aggregates can address a practical surgical imaging need, demonstrating clear translational potential (Figure ). Given that the emission at 1010 nm is located near the lower boundary of the NIR-II window, in vivo resolution remains suboptimal. Future efforts should focus on red-shifting emission into the NIR-IIb region (1500–1700 nm) through strategic substitution with electron-donating/withdrawing groups, as well as enhancing π-conjugation to improve quantum yield and overall imaging performance.

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(a) Structure of PCP-BDP2 and schematic illustration of the formation of the PCP-BDP2 nanoparticles. (b) Fluorescence emission spectra of PCP-BDP2 in different states. (c) In vivo fluorescence imaging of the lymphatic system in the NIR-II window via PCP-BDP2 nanoparticles. (d) Bioluminescence and NIR-II fluorescence signals from resected nodules in unguided and PCP-BDP2 NPs-guided groups. Reproduced from ref . Available under a CC BY 4.0 license. Copyright 2021 Li, K.; et al.

3.2. Tuning Photophysics and Aggregation of BODIPY J-Aggregates via Molecular Design

Precise structural modifications, such as introducing electron-donating/withdrawing groups and optimizing conjugation, enable tailored control over the photophysical properties and aggregation behavior of BODIPY-based J-aggregates. This strategy facilitates the regulation of spectral profiles, fluorescence quantum yields, and therapeutic functions (e.g., photothermal conversion, ROS generation), supporting versatile biomedical applications.

The Liu group utilized bridging ethylene units to regulate the J aggregation behavior of BODIPY.

The aggregate formed by BisBDP2 (modified with electron donating groups) and F127 exhibits an absorption wavelength of approximately 1300 nm, strong photoacoustic response characteristics, and 63% photothermal conversion efficiency (Figure a–d). These combined properties highlight its potential as a dual-modal contrast agent for deep-tissue photoacoustic imaging and guided tumor ablation. Although this study has contributed to expanding the family of NIR-II–absorbing organic dyes, improving their low fluorescence quantum yields will require further dedicated efforts in molecular design.

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(a) Structure of BisBDP2 and schematic of NIR-II window photoacoustic imaging-guided PTT with BisBDP2 J-aggregates. (b) The absorption spectrum of BisBDP2 NPs in PBS solution. (c) Infrared thermal imaging analysis of mice bearing orthotopic liver tumors following treatment with BisBDP2 NPs. (d) Photoacoustic imaging of orthotopic liver tumors at various time points post tail vein injection of BisBDP2 NPs. Reproduced from ref . Available under a CC BY-NC 4.0 license. Copyright 2022 Wang, X.; et al. (e) Structure of NOBDP-NO2 and illustration of F127-mediated assembly of BODIPY nanoparticles. (f) Normalized absorption and (g) emission spectra of NOBDP-NO2 in THF, NOBDP-NO2 NPs in water, and the film of NOBDP-NO2. (h) NIR-II fluorescence images for whole-body blood vessels, lymph node, fluorescence-guided lymph node resection, and secure information storage. Reproduced with permission from ref . Copyright 2023 Wiley-VCH. (i) Structure of BDP-F and construction of BDP-F NPs. the construction of the BDP-F nanoparticles. (j) Normalized spectra of BDP-F in THF and BDP-F NPs in water. (k) O2 •– generation of NOBDP-F and BDP-F. (l) NIR-II fluorescence imaging of HeLa tumor-bearing mice at 12 h post intravenous injection of BDP-F NPs (1000 nm long-pass filter). (m) In vivo NIR-II imaging of whole-body vasculature via BDP-F NPs (1319 nm long-pass filter). (n) In vivo thermal infrared imaging of HeLa tumor-bearing mice after 7 min of 808 nm laser irradiation (1.0 W/cm2) at 12 h following iv administration of BDP-F NPs or PBS. Reproduced from ref . Copyright 2024 American Chemical Society.

To enhance the fluorescence emission of BODIPY J-aggregates, Xiong et al. grafted electron-withdrawing nitro groups (-NO2) onto the 3,5-aryl and meso positions of BODIPY skeletons. This approach modulated the molecular slipping mode and enhanced intermolecular interactions, thereby enabling the formation of J-aggregates. Among them, the dye NOBDP-NO2 exhibits NIR-II emission at 1065 nm in the solid state under the synergistic effect of strong intermolecular hydrogen bonds and electrostatic repulsion, with a fluorescence quantum yield of 3.21%. Notably, coassembly of BODIPY dyes (including NOBDP-NO2) with amphiphilic F-127 enables the formation of uniform and stabilized nanoparticles that retain NIR-II J-aggregation characteristics. These nanoparticles can be applied in fluorescence imaging for whole-body blood vessels, lymph node, fluorescence-guided lymph node resection, and secure information storage. (Figure e–h). While this electron-withdrawing substituent strategy establishes a universal design strategy for developing organic dyes with enhanced emission in the aggregate state, achieving organic dyes with concurrently boosted NIR-II fluorescence, type I photodynamic therapy (PDT), and photothermal therapy (PTT) capabilities in their aggregated form remains an issue.

In follow up work, the group introduced an electron-withdrawing substituent at the 5-indolyl position of the BODIPY dye to induce the formation of tight J-aggregates. In this context, the combination of an electron-donating julolidine group at the meso position and an electron- withdrawing fluorine substituent on the indole creates a strong push–pull system. This enhances intermolecular charge transfer and hydrogen bonding, leading to efficient superoxide radical (O2 •–) generation in the aggregate state. In particular, the BDP-F nanoparticles exhibit a fluorescence emission at 1000 nm, while possessing excellent O2 •– generation capability and a high photothermal conversion efficiency of 50.9%. These characteristics allowed for NIR-II fluorescence-guided vasculature/tumor imaging and synergistic PDT/PTT (Figure i–n). This work presents a strategy to develop advanced phototheranostic agents with combined enhanced NIR-II fluorescence and type I PDT/PTT, paving the way for broad biomedical applications.

Overall, the cases above highlight the significant progress in applying BODIPY-based J-aggregates to advanced bioimaging. These aggregates have demonstrated vital capabilities in lymphatic system mapping, whole-body vasculature imaging, deep-tissue photoacoustic visualization, and image-guided surgery/therapy. The unique synergy between molecular engineering and supramolecular assembly in these systems allows the optical properties to be tailored for specific imaging modalities and biological targets. However, several key obstacles persist in the field of BODIPY-derived J-aggregates, such as low fluorescence quantum yields, suboptimal photothermal conversion in some systems, limited multifunctional integration, and concerns over clinical compatibility stemming from carrier dependence and unverified biosafety. Future developments may involve chalcogen substitution (S/Se), biomimetic membrane encapsulation, and enhanced π-conjugation to simultaneously improve optical performance, therapeutic efficacy, and translational potential.

4. Emerging Fluorophore-Based J-Aggregates

Beyond cyanine and BODIPY dyes, an increasing number of molecular scaffolds, including rhodamine analogues, fused-ring systems, and 2-(2′-hydroxyphenyl)-4­(3H)-quinazolinone (HPQ) derivatives, are being explored for constructing NIR-II J-aggregates. These materials offer tunable photophysical properties and diverse aggregation behaviors, supporting applications that require deeper tissue penetration, multimodal function, and improved clinical compatibility. This shift from single-scaffold optimization to multisystem innovation has enabled advances in areas such as aggregation control, fluorescence enhancement, and activatable imaging. Nevertheless, challenges in precise assembly guidance, performance trade-offs, and clinical adaptation remain. This section highlights representative advances, examines persistent limitations, and discusses future directions for the rational design of multifunctional J-aggregates.

4.1. Rhodamine Analogues

Yang et al. developed a crystal-aided aggregate synthesis (CAASH) approach to prepare stable and biocompatible JV-aggregates of rhodamine analogue ESi5-S. Its aggregation behavior is temperature-responsive and fully reversible, repeated heating-annealing treatments can alleviate aggregation disorders effectively. Owing to its high stability and biocompatibility in the bloodstream, the ESi5-S agg is well-suited for dual-channel in vivo imaging, using 1064 nm for bone structures and 808 nm for liver uptake as well as photoacoustic tomography of mouse bones (Figure ). This work transforms the development of J-aggregates from a largely serendipitous pursuit into a more rational endeavor. Although the broad absorption bands of NIR dyes hinder multiplexed imaging in the near-infrared region by introducing significant cross-talk, developing aggregates capable of pairing with ESi5-S agg holds the potential to overcome this limitation.

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(a) Crystal-aided aggregate synthesis (CAASH) using the ESi5 dye. (b) Upon repeated heating and annealing between 20 and 75 °C, the absorption spectra of ESi5-S in 10 mM PBS (pH 7.4) with 10% MeOH were recorded (left). Reversible absorbance variations of the monomer (867 nm) and ESi5-S agg (1038 nm) upon successive heating and annealing cycles (right). (c) In vivo fluorescence imaging of BALB/c mice using ESi5-S agg at 10 min (supine) and 180 min (supine and prone) after intravenous injection. (d) Photoacoustic imaging in BALB/c mice. Left: Photoacoustic images acquired without ESi5-S agg. Right: Photoacoustic images obtained at 180 min postintravenous injection of ESi5-S agg (2.5 mg/kg in PBS). Reproduced from ref . Available under a CC BY-NC-ND 4.0 license. Copyright 2025 Yao, C.; et al.

4.2. Fused-Ring Fluorophores

Fluorophore aggregation-induced emission quenching has long been a prominent challenge limiting the optimization of emission-dependent technologies. Hu et al. designed a hydrophobic fused-ring fluorophore 4F and encapsulated it in Pluronic F-127 to form nanoparticles (4F NP 1s). Although both dimers and monomers contribute to the NIR-II emission in 4F NP 1s, the dominant dimer is responsible for the aggregation-caused quenching (ACQ) due to its weak emission and intense intermolecular nonradiative decay. To address this issue, they developed a simple aggregation control strategy: reducing dimer population to suppress ACQ. This approach yielded ultrabright aggregates 4F NP 3s with a brightness approximately five times than that of indocyanine green (ICG). Owing to these unique properties, 4F NP 3s are capable of achieving improved resolution in blood vessel imaging (Figure ). While this study represents a significant advance in overcoming the ACQ challenge by developing highly emissive aggregated materials, the precision and stability of current dimer regulation methods remain insufficient, pointing to a key direction for future research breakthroughs.

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(a) Schematic illustration of the significant mitigation of NIR-II emission quenching in ring-fused fluorophores via dimer population modulation. (b) Molar extinction coefficient (blue) and photoluminescence quantum yield (ΦPL, red) of 4F nanoparticles (4F NPs). (c) Different filter-based NIR-II fluorescence imaging of blood vessels in live mice at 5 min postinjection of 4F NP 3s. Reproduced from ref . Available under a CC BY 4.0 license. Copyright 2025 Miao, X.; et al.

4.3. HPQ Derivatives

The clinical potential of conventional J-aggregates is limited by their instability and carrier-dependent stabilization strategies. In contrast, HPQ probes address these issues by rapidly forming insoluble fluorescent precipitates at the target site. This process inherently enhances stability and eliminates the need for carriers.

Zhang et al. developed a stable and controllable strategy for fabricating NIR-II J-aggregates by incorporating an HPQ unit with strong hydrogen-bonding interactions into the conjugated backbone of the dye. Beyond maintaining stability in aqueous media without relying on external carriers, the HPQ-based NIR-II J-aggregates exhibit controllable assembly behavior, tailorable optical performance, antidiffusion capabilities, and bright solid-state fluorescence. Using HPQ-LZ as a basis, they further developed an activatable probe HPQ-Zzh-B that responds to tumor-overexpressed ONOO–. This probe allowed for both long-term in situ tumor imaging in vivo and precise tumor resection under NIR-II navigation, which effectively reduced the incidence of lung metastasis (Figure ). This study provides a method for constructing high-stability and antidiffusion NIR-II J-aggregates, overcoming the limitation of conventional J-aggregates’ reliance on carriers. Given that the emission of these HPQ-based J-aggregates is currently below 1000 nm, a key future direction involves pushing it into the ideal NIR-IIb range (1500–1700 nm), thereby enhancing deep-tissue penetration.

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(a) The design of NIR-II-J-aggregates. (b) The reaction of HPQ-Zzh-B with ONOO–. (c) Spectral characteristics of HPQ-Zzh-B with ONOO–. (d) NIR-II in vivo imaging prior to surgical navigation with HPQ-Zzh-B, λex = 808 nm, collection channel:1000–1700 nm. (e) Antidiffusion experiments in the tumor area based on NIR-II fluorescence from HPQ-Zzh-B. Adapted and reproduced from ref . Available under a CC BY 4.0 license. Copyright 2023 Li, Z.; et al.

In general, the development of emerging fluorophore-based J-aggregates still face various challenges: inadequate control over dimer populations, performance trade-offs between brightness,stability, and deep-tissue penetration, and limited clinical translation due to unresolved formulation complexity. Several promising pathways could lead to J-aggregates with superior order and function. These include harnessing computational design to guide their assembly, incorporating pH- or enzyme-responsive switches to control dimer formation, or using biomimetic membranes as protective shells.

5. Concluding Remarks and Perspective

J-aggregates, as supramolecular assemblies with tunable photophysical properties, have emerged as a distinctive platform reshaping the landscape of chemical and biomedical imaging, with expanding implications in theranostics. Their defining characteristicsred-shifted narrow absorption, high fluorescence quantum yield, and efficient exciton transportaddress critical limitations of conventional imaging materials, such as constrained tissue penetration within the visible/near-infrared region I (NIR-I) window, single-modal functional restrictions, and the disconnect between imaging and therapeutic capabilities. Notable advancements in their application to NIR-II deep-tissue imaging, fluorescence imaging (FLI)/photoacoustic imaging (PAI) dual-modal diagnosis, and integrated “imaging-therapy-monitoring” systems underscore their unique value in biomedical contexts, providing a foundational framework for advancing precision medicine. The optical properties of these representative luminophors are summarized in Table .

1. Summary of Optical Properties of Representative Luminophors.

Luminophor design strategy of NIR-II J-aggregates λabs (nm) λem (nm) ε (M–1·cm–1) ΦF (%) solvent
IR-140 electrostatic interactions 826 875 1.7 × 105 20 DMSO
IR-140   1042 1043 3.9 × 105 0.012 35% DMSO/0.9% NaCl in H2O
IR-140@HMSNs-PEG   1038 1047 - - PBS
FD-1080 self-assembly of amphiphilic dye 1012 1056 5.6 × 104 0.18 MeOH
FD-1080/DMPC   1360 1370 5.0 × 104 0.0545 PBS
CYJ1059 introducing steric hindrance 881 925 2.63 × 105 1.92 DMSO
CYJ1059@F127   1059 1060 2.94 × 105 0.21 HEPES
CYJ981   838 868 - - DMSO
CYJ981@F127   980 - - - HEPES
CyN-OMe modulation of intramolecular electronic distribution and intermolecular interactions 875 - - <0.1 DMSO
Lipo@CyN-OMe   1030 - - - PBS
IR-1061 electron delocalization and electrolyte synergy 1073 1100 - - DMSO
J IR‑1061   1580 - - -  
RENPs-J IR‑1061   1580 - - -  
PCP-BDP2 The steric and conjugative effects 722 795 - - CH2Cl2
PCP-BDP2@F127   750 1010 - 6.4 PBS
BisBDP2 bridging ethylene units 1112 1314 7.8 × 104 - CH2Cl2
BisBDP2@F127   1273 1331 9.3 × 104 - PBS
NOBDP-NO2 modulating the molecular slipping mode and enhancing intermolecular interactions 655 960 8.6 × 104 0.05 (>900 nm) THF
NOBDP-NO2 NPs   807 925/1055 9.2 × 103 0.51(>900 nm) H2O
BDP-F Creating strong push–pull system 682 885 1.013 × 105 0.014 THF
BDP-F   792 990 6.01 × 104 0.181 10% THF in H2O
BDP-F NPs   840 1000 1.65 × 104 0.18 H2O
ESi5-S CAASH 696/1038/1098 1106 8.8 × 104 0.06 PBS
4F reducing dimer population 760 940 6.4 × 104 17.1 THF
4F NP 1s   840 1050 6.8 × 104 2.6 H2O
4F NP 3s   840 1040 9.5× 104 7.5 H2O
HPQ-Zzh hydrogen-bonding interactions 605 910 - 0.037 DPBS + 1% Tween
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a

The maximal absorption wavelength.

b

The maximal emission wavelength. ΦF is the relative quantum yield. “-” indicates that the parameter was not reported in the original literature.

Despite these progresses, the translation of J-aggregates from laboratory breakthroughs to clinical practice depends on overcoming several interrelated barriers, with biocompatibility, fluorescence stability, tissue penetration, and systemic safety evaluation being critical. Four key aspects are outlined below: (1) many systems rely on synthetic carriers (e.g., polymers, silica) with incompletely defined long-term fate and potential to trigger immune responses. Comprehensive in vivo toxicology and drug metabolism studies following standardized protocols are scarce, raising concerns for human use. Furthermore, the common strategy of polymer encapsulation to enhance stability often creates a trade-off with the sensitivity of activatable probes. (2) The propensity of J-aggregates to dissociate in physiological environments (due to pH, ionic strength, protein binding) harms signal precision and can lead to false negatives, reducing diagnostic reliability. (3) While working in the NIR-II window is advantageous, the emission of most aggregates falls in the NIR-IIa region (1000–1350 nm). Achieving bright and stable emission in the NIR-IIb region (1500–1700 nm) is critical for maximizing penetration depth and improving signal-to-background ratio in deep tissues. (4) A major problem is the lack of consistent testing methods and complete safety evaluation plans across different studies. This makes it hard to compare results and slows down approval for medical use.

Beyond these critical translational factors, fundamental scientific challenges remain. A primary obstacle is the lack of generalizable design principles, which limits scalable application and leaves the potential of asymmetric dyes and hybrid systems underexplored. Finally, the mismatch between function and application persistsmany J-aggregate systems fail to meet theranostic demands due to low quantum yields or energy conversion efficiencies (some below 50%), requiring precision design tailored to specific needs.

Looking forward, unlocking the full biomedical potential of J-aggregates will require progress in three interconnected directions. First, expanding the material paradigm through structural innovation: exploring asymmetric chromophores (e.g., hemicyanines with tunable electronic effects) and organic–inorganic hybrid J-aggregates could broaden the NIR-II spectral window (e.g., extending to 1500–1700 nm for deeper tissue penetration) and introduce new functionalities (e.g., enhanced ROS generation for photodynamic therapy or magnetic resonance imaging compatibility via inorganic doping). Developing “smart responsive scaffolds” that trigger assembly/dissociation in response to biological signals (e.g., pH, enzymes, ROS) would enable precise regulation of aggregation states and signal activation in target tissues, mitigating false positives. Second, advancing multimodal integration and functional synergy: leveraging J-aggregates’ efficient exciton transport, future systems should move beyond FLI/PAI dual-modality to integrate PTT, photodynamic therapy, and drug delivery, creating closed-loop “imaging-drug release-therapy-response monitoring” systems. For example, loading J-aggregates into exosome carriers could enable targeted tumor delivery, where NIR-II imaging guides photothermal/photodynamic therapy, and PAI monitors therapy-induced tissue changes, achieving full-process precision theranostics. Third, accelerating clinical translation through interdisciplinary collaboration: materials scientists, pharmacologists, and clinicians must collaborate to overcome translational barriers, including enhancing targeting and reducing nonspecific adsorption via nanocarrier technologies (e.g., liposomes, exosomes), establishing unified characterization standards (e.g., mandatory verification of exciton coupling energy barriers and in vitro/in vivo stability) to ensure reproducibility, and conducting large-scale animal studies to validate long-term safety and efficacy for clinical trials. The ultimate translational value of NIR-II J-aggregates lies in their potential to become core components of closed-loop theranostic systems. Achieving this requires the development of stable, target-activated formulations for specific clinical scenarios, such as real-time tumor margin delineation during minimally invasive surgery or in situ monitoring of inflammatory activity, validated through robust preclinical safety and efficacy studies.

In summary, J-aggregates represent a transformative platform at the interface of supramolecular chemistry and biomedicine. While current challengesfrom material design to clinical validationare significant, targeted innovations in structure, function, and standards, combined with interdisciplinary collaboration, will drive their evolution from basic research to practical applications. As these systems mature into robust, clinically viable tools, they are expected to become a core technology in next-generation precision medicine, enabling breakthroughs in deep-tissue diagnosis, targeted therapy, and real-time therapeutic monitoring, ultimately bridging supramolecular innovation and improved patient outcomes.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 22277032) and the startup fund from HUST.

The authors declare no competing financial interest.

Published as part of Chemical & Biomedical Imaging special issue “New Chemistry and Emerging Technologies for Molecular Imaging”.

References

  1. Liu S., Dong W., Gao H., Song Z., Cheng Z.. Near-Infrared-II Fluorescent Probes for Analytical Applications: From In Vitro Detection to In Vivo Imaging Monitoring. Acc. Chem. Res. 2025;58:543–554. doi: 10.1021/acs.accounts.4c00671. [DOI] [PubMed] [Google Scholar]
  2. Xu J., Zheng X., Ren T.-B., Shi L., Yin X., Yuan L., Zhang X.-B.. Recent advances in near-infrared-II organic J-aggregates for bio-applications. Coord. Chem. Rev. 2025;528:216379. doi: 10.1016/j.ccr.2024.216379. [DOI] [Google Scholar]
  3. Sun J., Cheng W., Liu X., Xiang H., Ruan C., Chen F., Yao C.. Gold clusters: A promising NIR-II probe for bioimaging and biosensing. Coord. Chem. Rev. 2025;533:216544. doi: 10.1016/j.ccr.2025.216544. [DOI] [Google Scholar]
  4. Xu J., Zhu N., Du Y., Han T., Zheng X., Li J., Zhu S.. Biomimetic NIR-II fluorescent proteins created from chemogenic protein-seeking dyes for multicolor deep-tissue bioimaging. Nat. Commun. 2024;15:2845. doi: 10.1038/s41467-024-47063-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Zhao M., Chen X.. Recent advances in NIR-II materials for biomedical applications. Acc. Mater. Res. 2024;5:600–613. doi: 10.1021/accountsmr.4c00025. [DOI] [Google Scholar]
  6. Chen Z., Zhang Z., Zeng F., Wu S.. Visualizing detection of diabetic liver injury by a biomarker-activatable probe via NIR-II fluorescence imaging. Chem. Biomed. Imaging. 2023;1:716–724. doi: 10.1021/cbmi.3c00030. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Dou W., Guo C., Zhu L., Qiu P., Kan W., Pan Y., Zang Y., Dong L., Li J., Tan Y., Wang H., He X.. Targeted near-infrared fluorescence imaging of liver cancer using dual-peptide-functionalized albumin particles. Chem. Biomed. Imaging. 2024;2:47–55. doi: 10.1021/cbmi.3c00078. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Li B., Pang E., Zhao S., Deng G., Wang S., Wang B., Wu J., Niu G., Song X., Lan M.. Aggregation-enhanced photophysical performance of D-π-A structured hemicyanine for NIR-II fluorescent and photoacoustic imaging-guided photothermal therapy. Chem. Biomed. Imaging. 2023;1:541–549. doi: 10.1021/cbmi.2c00004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Ou Y.-F., Ren T.-B., Yuan L., Zhang X.-B.. Molecular design of NIR-II polymethine fluorophores for bioimaging and biosensing. Chem. Biomed. Imaging. 2023;1:220–233. doi: 10.1021/cbmi.3c00040. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Yu Q., Zhou J., Wang H., Liu Y., Zhou H., Kang B., Chen H.-Y., Xu J.-J.. A multiple-response cascade nanoreactor for starvation and deep catalysis chemodynamic assisted near-infrared-II mild photothermal therapy. Chem. Biomed. Imaging. 2023;1:242–250. doi: 10.1021/cbmi.2c00003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Pan Y., Weng X., Jia M., Miao X., Zhao H., Zhang J., Hu W., Fan Q.. Engineering bright J-aggregates through manipulation of electron acceptor for in vivo NIR-II fluorescence imaging. J. Innovative Opt. Health Sci. 2025;18:2541002. doi: 10.1142/s1793545825410020. [DOI] [Google Scholar]
  12. Liu G., Wang C., Lu G.. The second near-infrared (NIR-II) window excitable/emissive organic/polymeric fluorescent molecules for bioimaging application. J. Innovative Opt. Health Sci. 2025;18:2530002. doi: 10.1142/s1793545825300022. [DOI] [Google Scholar]
  13. Gao Y., Zhang C., Zhu L., Du Z., Ma R., Guo L., Alifu N., Zhang X.. Ultrabright quantum dots assisted in vivo NIR-II fluorescence microscopic imaging for brain metastases in triple-negative breast cancer. J. Innovative Opt. Health Sci. 2025;18:2441001. doi: 10.1142/s1793545824410013. [DOI] [Google Scholar]
  14. Miao X., Jia M., Weng X., Zhang J., Pan Y., Zhao H., Yu Z., Fan Q., Hu W.. Alleviating NIR-II emission quenching in ring-fused fluorophore via manipulating dimer populations for superior fluorescence imaging. Light:Sci. Appl. 2025;14:109. doi: 10.1038/s41377-025-01787-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Hu X., Fang Z., Zhu C., Yang Y., Yang Z., Huang W.. Crucial breakthrough of BODIPY-based NIR-II fluorescent emitters for advanced biomedical theranostics. Adv. Funct. Mater. 2024;34:2401325. doi: 10.1002/adfm.202401325. [DOI] [Google Scholar]
  16. Ou C., Zhao Z., An L., Zheng L., Gao F., Zhu Q., Wang W., Shao J., Xie L., Dong X.. J-aggregate promoting NIR-II emission for fluorescence/photoacoustic imaging-guided phototherapy. Adv. Healthcare Mater. 2024;13:2400846. doi: 10.1002/adhm.202400846. [DOI] [PubMed] [Google Scholar]
  17. Wu K., Yang R., Song X., Ju H., Liu Y.. Recent advances in NIR-II molecular aggregates and applications in the biomedical field. Chemosensors. 2025;13:67. doi: 10.3390/chemosensors13020067. [DOI] [Google Scholar]
  18. Sun G., Zhang Y., Zhou N., Huo F., Yin C.. Recent advances in the construction, imaging and phototherapy applications of NIR-II J-aggregates based on different fluorophores. Dyes Pigm. 2025;243:113054. doi: 10.1016/j.dyepig.2025.113054. [DOI] [Google Scholar]
  19. Xu S., Liu H.-W., Huan S.-Y., Yuan L., Zhang X.-B.. Recent progress in utilizing near-infrared J-aggregates for imaging and cancer therapy. Mater. Chem. Front. 2021;5:1076–1089. doi: 10.1039/D0QM00557F. [DOI] [Google Scholar]
  20. Li Z., Liang P., Xu L., Zhang X., Li K., Wu Q., Lou X., Ren T., Yuan L., Zhang X.. In situ orderly self-assembly strategy affording NIR-II-J-aggregates for in vivo imaging and surgical navigation. Nat. Commun. 2023;14:1843. doi: 10.1038/s41467-023-37586-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Wurthner F., Kaiser T., Saha-Möller C. R.. J-aggregates: from serendipitous discovery to supramolecular engineering of functional dye materials. Angew. Chem., Int. Ed. 2011;50:3376–3410. doi: 10.1002/anie.201002307. [DOI] [PubMed] [Google Scholar]
  22. Spearman A., Lin E., Mobley E., Chmyrov A., Arús B., Turner D., Garcia C., Bui K., Rowlands C., Bruns O., Sletten E.. High-resolution multicolor shortwave infrared dynamic in vivo imaging with chromenylium nonamethine dyes. J. Am. Chem. Soc. 2025;147:17384–17393. doi: 10.1021/jacs.5c03673. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Meador W. E., Lin E. Y., Lim I., Friedman H. C., Ndaleh D., Shaik A. K., Hammer N. I., Yang B., Caram J. R., Sletten E. M., Delcamp J. H.. Silicon-RosIndolizine fluorophores with shortwave infrared absorption and emission profiles enable in vivo fluorescence imaging. Nat. Chem. 2024;16:970–978. doi: 10.1038/s41557-024-01464-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Lim I., Yu Lin E., Garcia J., Jia S., Sommerhalter R. E., Ghosh S. K., Gladysz J. A., Sletten E. M.. Shortwave infrared fluorofluorophores for multicolor in vivo imaging. Angew. Chem., Int. Ed. 2023;62:e202215200. doi: 10.1002/anie.202215200. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Cosco E. D., Arus B. A., Spearman A. L., Atallah T. L., Lim I., Leland O. S., Caram J. R., Bischof T. S., Bruns O. T., Sletten E. M.. Bright chromenylium polymethine dyes enable fast, four-color in vivo imaging with shortwave infrared detection. J. Am. Chem. Soc. 2021;143:6836–6846. doi: 10.1021/jacs.0c11599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Cosco E. D., Spearman A. L., Ramakrishnan S., Lingg J. G. P., Saccomano M., Pengshung M., Arús B. A., Wong K. C. Y., Glasl S., Ntziachristos V., Warmer M., McLaughlin R. R., Bruns O. T., Sletten E. M.. Shortwave infrared polymethine fluorophores matched to excitation lasers enable non-invasive, multicolour in vivo imaging in real time. Nat. Chem. 2020;12:1123–1130. doi: 10.1038/s41557-020-00554-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Chen W., Cheng C. A., Cosco E. D., Ramakrishnan S., Lingg J. G. P., Bruns O. T., Zink J. I., Sletten E. M.. Shortwave infrared imaging with J-aggregates stabilized in hollow mesoporous silica nanoparticles. J. Am. Chem. Soc. 2019;141:12475–12480. doi: 10.1021/jacs.9b05195. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Cao W., Sletten E. M.. Fluorescent cyanine dye J-aggregates in the fluorous phase. J. Am. Chem. Soc. 2018;140:2727–2730. doi: 10.1021/jacs.7b11925. [DOI] [PubMed] [Google Scholar]
  29. Deng G., Zhang S., Peng X., Ma G., Liu L., Tan Y., Gong P., Tang B. Z., Cai L., Zhang P.. Methylene Blue: An FDA-Approved NIR-II Fluorogenic Probe with Extremely Low pH Responsibility for Hyperchlorhydria Imaging. Chem. Biomed. Imaging. 2024;2:683–688. doi: 10.1021/cbmi.4c00011. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Hu X., Zhu C., Sun F., Chen Z., Zou J., Chen X., Yang Z.. J-Aggregation strategy toward potentiated NIR-II fluorescence bioimaging of molecular fluorophores. Adv. Mater. 2024;36:2304848. doi: 10.1002/adma.202304848. [DOI] [PubMed] [Google Scholar]
  31. Sun C., Li B., Zhao M., Wang S., Lei Z., Lu L., Zhang H., Feng L., Dou C., Yin D., Xu H., Cheng Y., Zhang F.. J-aggregates of cyanine dye for NIR-II in vivo dynamic vascular imaging beyond 1500 nm. J. Am. Chem. Soc. 2019;141:19221–19225. doi: 10.1021/jacs.9b10043. [DOI] [PubMed] [Google Scholar]
  32. Sun C., Sun X., Pei P., He H., Ming J., Liu X., Liu M., Zhang Y., Xia Y., Zhao D., Li X., Xie Y., Zhang F.. NIR-II J-aggregates labelled mesoporous implant for imaging-guided osteosynthesis with minimal invasion. Adv. Funct. Mater. 2021;31:2100656. doi: 10.1002/adfm.202100656. [DOI] [Google Scholar]
  33. Zhang C., Wu Y., Zeng F., Wen Y., Chen J., Deng G., Zhang L., Zhao S., Wu S., Zhao Y.. Structurally modulated formation of cyanine J-aggregates with sharp and tunable spectra for multiplexed optoacoustic and fluorescence bioimaging. Angew. Chem., Int. Ed. 2024;63:e202406694. doi: 10.1002/anie.202406694. [DOI] [PubMed] [Google Scholar]
  34. Shi T., Chen X., Li X., Li X., Zhao Y., Zhang H., Han F., Cai L., Zhou X., Su Y., Sun W., Du J., Fan J., Peng X.. Charge transfer-mediated J-aggregates of azaindole cyanine with 160 nm absorption redshift for efficient NIR-II photothermal tumor therapy. ACS Nano. 2025;19:27845–27859. doi: 10.1021/acsnano.5c09082. [DOI] [PubMed] [Google Scholar]
  35. Wu K., Chao Z., Aji S., Zhu Y., Zhao H., An Y., Ju H., Liu Y.. Peroxynitrite responsive second near-infrared cyanine dye J-aggregate for drug-induced hepatotoxicity monitoring. Chem. Biomed. Imaging. 2025;3:379–386. doi: 10.1021/cbmi.4c00111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Zhu Y., Wu F., Zheng B., Yang Y., Yang J., Xiong H.. Electron-withdrawing substituents enhance the type I PDT and NIR-II fluorescence of BODIPY J aggregates for bioimaging and cancer therapy. Nano Lett. 2024;24:8287–8295. doi: 10.1021/acs.nanolett.4c01339. [DOI] [PubMed] [Google Scholar]
  37. Zhu Y., Wu P., Liu S., Yang J., Wu F., Cao W., Yang Y., Zheng B., Xiong H.. Electron-withdrawing substituents allow boosted NIR-II fluorescence in J-type aggregates for bioimaging and information encryption. Angew. Chem., Int. Ed. 2023;62:e202313166. doi: 10.1002/anie.202313166. [DOI] [PubMed] [Google Scholar]
  38. Wang X., Jiang Z., Liang Z., Wang T., Chen Y., Liu Z.. Discovery of BODIPY J-aggregates with absorption maxima beyond 1200 nm for biophotonics. Sci. Adv. 2022;8:eadd5660. doi: 10.1126/sciadv.add5660. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Li K., Duan X., Jiang Z., Ding D., Chen Y., Zhang G. Q., Liu Z.. J-aggregates of meso-[2.2]­paracyclophanyl-BODIPY dye for NIR-II imaging. Nat. Commun. 2021;12:2376. doi: 10.1038/s41467-021-22686-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Yao C., Wei R., Luo X., Zhou J., Zhang X., Lu X., Dong Y., Chu R., Sun Y., Wang Y., Xia W., Qu D., Liu C., Ren J., Ge G., Chen J., Qian X., Yang Y.. A stable and biocompatible shortwave infrared nanoribbon for dual-channel in vivo imaging. Nat. Commun. 2025;16:4. doi: 10.1038/s41467-024-55445-x. [DOI] [PMC free article] [PubMed] [Google Scholar]

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