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. 2026 Feb 23;11(9):15055–15061. doi: 10.1021/acsomega.5c12062

An MOF–Graphene Interface for Efficient Electrochemical Sensing of Water-Soluble Organic Dyes

Youssef A Darwish †, Eman Wahid †, Hager G Abdel-Mohey †, Samar El-Kassas ‡, Rabeay Y A Hassan §, Saad Makhseed ∥, Mohamed H Alkordi †,*
PMCID: PMC12980410  PMID: 41835597

Abstract

Differential detection and quantification of organic dyes in aqueous media are demonstrated utilizing an electrochemical method on a nanocomposite of UiO-66-NH2 MOF deposited on graphene nanoplatelets (MOF@G). The selected organic dyes are anionic molecules with overlapping UV–vis absorption bands, which makes it cumbersome to detect, differentiate, and quantify each component in a solution mixture. The method presented herein provides for such detection and differentiation utilizing the tailored properties of the nanocomposite MOF@G, where the high porosity and adsorption capacity of the MOF toward soluble organic molecules, alongwith the high electronic conductivity of the G support, synergistically harnessed to provide a facile method for rapid and sensitive detection that can be further exploited toward other types of solution-based electrochemical detection of small organic molecules. A low detection limit of ∼2 ppm and a large dynamic linear range up to 12 ppm in an aqueous acidic solution are reported.

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Introduction

Due to pressing needs for applications in industrial control, environmental protection, medical diagnosis, and food safety, among others, the quest for efficient, reliable, and sensitive detection methods for small molecules, especially in solution, is rapidly expanding. Electrochemical detection methods are reliable, efficient, portable, and inexpensive as compared with other more sophisticated detection methods like mass spectrometry, fluorescence, absorption, or emission spectroscopy, justifying the growing interest in electrochemical sensors. The large number of electrochemical detection targets, including toxins, metabolites, biomarkers, pollutants, and drug molecules, combined with the ability of such techniques to rapidly detect specific targets in complex matrices, provides for real-time monitoring as well. Despite such attributes of electrochemical sensors, certain challenges persist in enhancing the sensitivity and specificity of such sensors, especially toward soluble small organic molecules.

Significant progress in the design and synthesis of highly porous and chemically stable metal–organic frameworks (MOFs), capable of efficient guest uptake from aqueous media, stimulated strong interest in the application of such a novel family of materials in electrochemical sensors. , A key challenge faced by this family of compounds is their intrinsic low electronic conductivity, limiting their direct utilization in certain applications where efficient electron mobility is required, including electrocatalysis, energy storage, and electrochemical sensing. ,− One of the feasible solutions to this challenge is the construction of hybrid materials, including MOFs as porous sorbents, and conductive carbon materials like graphene (G) or multiwalled carbon nanotubes (MWCNTs). , Indeed, previous reports demonstrated that designed synthesis effectively resulted in nanocomposites of MOFs atop G , and MWCNTs, with demonstrated performance in electrocatalysis. , Additionally, MOF thin layers can directly be constructed on conductive electrodes through solvothermal synthesis from their soluble precursors, , enabling their direct utilization in constructing electrochemical sensors for a wide range of applications. Accordingly, in this study, a new sensing platform composed of UiO-66-NH2@G was designed, optimized, and applied for the simultaneous voltametric analysis of soluble organic dyes.

Results and Discussion

Herein, we demonstrate that the water-stable MOF@G nanocomposite (UiO-66-NH2@G) is successfully utilized as a sensing material for the rapid and efficient electrochemical detection and differentiation of a family of anionic soluble organic dyes. The synergy between the high surface area and enhanced adsorptive behavior of the MOF and the excellent electronic conductivity of G can be attained by the solvothermal synthesis of the MOF atop suspended graphene platelets in the synthesis mixture. Due to the insoluble nature of MOFs, solution-based deposition techniques that can be used to deposit polymers on conductive surfaces cannot be applied here. However, as the MOF synthesis typically progresses from soluble metal salts and organic linker precursors, introducing suspended G into the synthesis mixture, aided by physical agitation, successfully resulted in the isolation of MOF crystallites uniformly deposited on G sheets. Seeding on the G surface during the solvothermal synthesis of the MOF and subsequent crystal growth on G sheets enabled the isolation of UiO-66-NH2@G. The scanning electron microscopy image (SEM) of the isolated UiO-66-NH2@G (Figure ) demonstrated the uniformity of the deposited layer of UiO-66-NH2 atop G sheets. The energy-dispersive X-ray photoelectron emission mapping (EDX) further confirmed the homogeneous distribution of the Zr, O, and N elements within the UiO-66-NH2 crystallites (Figure ). X-ray diffraction (XRD) was then utilized to further confirm the construction of UiO-66-NH2@G (Figure ). The XRD pattern for UiO-66-NH2@G essentially matched that of a sample of UiO-66-NH2 prepared without inclusion of graphene platelets, with the exception of an additional peak at 2θ = 26.5° ascribed to the graphitic (002) diffraction from the few-layer graphene platelets. The XRD patterns therefore clearly demonstrated the attainment of the intended pure phase crystalline UiO-66-NH2 MOF deposited on the G platelets. Fourier transform infrared spectroscopy (FTIR) was also utilized to ascertain the presence of UiO-66-NH2 in the composite (Figure ). The presence of the MOF characteristic FTIR absorption bands was observed for CO asymmetric stretching (1575 cm–1) and CO symmetric stretching (1431 cm–1), as well as the aromatic CC stretching (1386 cm–1).

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(a) SEM image of UiO-66-NH2@G showing complete coverage of the MOF crystallites over graphene platelets, (b) SEM for the EDX mapping of the sample showing uniform distribution of (c) zirconium, (d) oxygen, and (e) nitrogen elemental mapping within the sample.

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XRD patterns of UiO-66-NH2@G and UiO-66-NH2; the expanded part of the XRD patterns demonstrated an additional peak at 26.5 for the graphitic (002) diffraction in UiO-66-NH2@G.

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FTIR spectra for UiO-66-NH2 and UiO-66-NH2@G.

The porosity of the material was also assessed using gas sorption isotherms (N2 at 77 K), as shown in Figure . The N2 sorption isotherms in Figure a demonstrated type I isotherms for UiO-66-NH2, while UiO-NH2@G demonstrated a slight tendency toward type IV isotherms, ascribed to the sample texture due to packing of the MOF@G nanoplatelets. The Brunauer–Emmett–Teller (BET) surface areas for the two samples were calculated to be 1160 and 1003 m2/g, respectively. Notably, the pore size distribution (PSD) plot in Figure b demonstrated more clearly the difference between the pristine MOF and its composite with G, where the PSD for UiO-66-NH2 demonstrated sharp peaks for micropores in the range of 0.6–1.4 nm, while UiO-66-NH2@G still demonstrated such micropores albeit with extra peaks for pores at 3.2 and 5.2 nm, which can be ascribed to the sample texture and/or packing of MOF@G platelets within the composite.

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(a) N2 sorption isotherms for UiO-66-NH2 and UiO-66-NH2@G. (b) Corresponding PSD plots

Further characterization of UiO-66-NH2@G was conducted utilizing X-ray photoelectron spectroscopy (XPS), as shown in Figure . The detailed XPS line spectra for UiO-66-NH2@G when compared to those in UiO-66-NH2 revealed far enhanced intensity in the C 1s line spectrum at 284.1 eV, ascribed to SP2 CC in graphene while essentially maintaining the same characteristic peaks of N 1s at 399.5 eV (−NH2) and 401 eV (−NH3 +), as found in the UiO-66-NH2 sample. The Zr 3d line spectra were also quite similar in UiO-66-NH2 and UiO-66-NH2@G.

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X-ray photoelectron spectra (XPS) for UiO-66-NH2 and UiO-66-NH2@G, showing the C 1s, N 1s, and Zr 3d detailed line spectra.

The UiO-66-NH2@G presented an ideal platform designed as an efficient MOF–graphene interface for electrochemical detection of soluble organic dyes, specifically due to (i) the stability of the Zr–MOF in aqueous media in neutral, acidic, and alkaline pH, (ii) the presence of protonated aromatic amine within the framework, as confirmed by XPS analysis, with expected role in facilitating electrostatic-assisted sorption of anionic dyes within the framework, (iii) the high surface area of UiO-66-NH2, providing ample space for dye accumulation at the electrode–electrolyte interface, and (iv) the inclusion of electronically conductive G within the matrix, enhancing electron transfer efficiency for the sensor. The water stability of the material is an a priori requirement for any meaningful design of a sensor capable of detecting water-soluble analytes. UiO-66-NH2 MOF is by far one of the most water-stable MOFs and is also tolerant to a wide pH range of the solution. Its counterpart (UiO-66) is also water-stable but lacks amine functionality, which is essential in this design for electrostatically assisted sorption of anionic molecules. The presence of electronically conductive G platelets within UiO-66-NH2@G is equally significant to enable electron transport within the sensing element, providing charge transport between the analyte and the electrode. As will be shown later, an attempt to utilize UiO-66-NH2 as a sensing element did not provide detectable signals at essentially similar experimental conditions utilized for UiO-66-NH2@G. Additionally, if only G was deposited on the glassy carbon electrode (GCE), no discernible signal was recorded for the analyte, further supporting the necessity to include both the MOF and G interface to establish an efficient electrochemical sensor for the detection of water-soluble analytes.

The UiO-66-NH2@G was then utilized to prepare an ink by dispersion in isopropanol, addition of Nafion as a binder, and then casting on a glassy carbon electrode (GCE) for electrochemical detection of soluble organic dyes. The dyes selected for this study were methyl orange (MO), Congo red (CR), and Eriochrome Black T (EBT). The selected analytes are all azo dyes of organosulfonic acids with interfering visible absorption spectra (Figure a), making it difficult to differentiate using UV–vis absorption spectroscopy. The cyclic voltammetry (CV) scans of the three dyes on the MOF@G demonstrated analyte-specific redox couples, enabling facile detection using the CV technique (Figure b–d). The MO demonstrated oxidation peaks at 0.05, 0.17, 0.27, and 0.49 V, the CR demonstrated oxidation peaks at 0.05, 0.17, and 0.25 V and a characteristic reduction peak at 0.13 V, and EBT demonstrated oxidation peaks at 0.05, 0.2, and 0.31 V vs Ag/AgCl. Concentration-dependent peak current was also recorded for the three dyes, where a calibration plot was made utilizing each specific peak in the three dyes (see Figure ). The detection limit for all three dyes was 1.2 ppm in a slightly acidified aqueous solution using 50 mM H2SO4 as the supporting electrolyte, pH 1.5. Additionally, the dependence of peak current on scan rate was studied for a 10 ppm MO solution, utilizing UiO-66-NH2@G as the sensing element (Figure ). The observed linear relationship between the peak current as a function of the square root of scan rate indicated a diffusion-controlled process, where diffusion of the soluble organic dye molecules from the bulk of the electrolyte and into the pores of the MOF is expected.

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(a) UV–vis spectra of the MO, CR, and EBT dyes at the same concentration. CV scans in 50 mM H2SO4 for (b) EBT, (c) CR, and (d) MO utilizing the UiO-66-NH2@G/GCE working electrode, and all potentials measured against the Ag/AgCl reference electrode.

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Calibration plot for the three different dyes (MO, CR, and EBT), indicating the peak potential utilized for each one and the R 2 value for the linear fitting.

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Peak current–scan rate dependence for the MO detected on UiO-66-NH2@G.

Due to the high surface area and electronically insulating nature of the MOF, a relatively high capacitive current was observed in all CV scans recorded. However, distinctive redox couples were observed still for the different analytes even at a low bulk concentration (range of 1–3 ppm), indicating that the MOF acted as a porous solid sorbent for dyes, enabling higher relative concentrations at the vicinity of the electrode, and thus facilitated a much lower detection limit as compared to bare GCE or graphene cast on the GCE. The previously documented excellent adsorption properties of the UiO-66-NH2 MOF toward several small molecules and metal ions , facilitated the enhanced detection limit of the anionic dyes studied herein.

The pronounced preferential sorption of anionic guest molecules by UiO-66-NH2 was previously documented and ascribed to electrostatic and/or charge-assisted H-bond interactions between the anionic guest molecules and the cationic MOF crystallites. Utilization of UiO-66-NH2 in water treatment through the adsorptive removal of contaminant molecules was previously demonstrated. Working under slightly acidic conditions results in the buildup of a positive surface charge on the UiO-66-NH2, which results in selective uptake of anionic guest molecules over neutral or cationic ones. In this context, the adsorption of the dyes from aqueous solution into the MOF layer can be described as a preconcentration step, resulting in a higher relative concentration of the dye molecules at the immediate vicinity of the electrode and thus facilitating a lower detection limit as compared to only graphene deposited at GCE (Figure a). The CV scan recorded utilizing graphene ink immersed in a 10 ppm solution of MO demonstrated high capacitive current, characteristic of the high surface area and enhanced electronic conductivity of graphene, albeit with no discernible peaks for the MO analyte. This can be explained considering the nonspecific, weak binding between G and such a charged soluble molecule. Interestingly, in another control experiment, where only the MOF, with no graphene content, was deposited on the GCE, no signal was observed for MO, indicating the crucial role of graphene in facilitating electron transfer at the MOF/electrode interface to detect the adsorbed dye molecules (Figure b). Enhancing electronic conductivity in MOF composites with several types of conductive carbon was recently explored for applicability in electrochemical sensing applications (Table ).

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(a) CV scan of graphene deposited on GCE demonstrating high capacitive current with no discernible signal for MO, and (b) comparison of the MOF and MOF@G deposited on GCE, where the pristine MOF did not demonstrate appreciable current response due to its insulating nature. All experiments were conducted in the same solution of 10 ppm MO in 50 mM H2SO4.

1. Representative Previous Reports on the MOF Composite with Conductive Carbon for Electrochemical Sensing Application.

analyte composite material MOF type carbon type detection method LOD linear range sensitivity/performance refs
dopamine Co-TCPP(Fe)/rGO/Nafion Co-TCPP(Fe) (2D MOF) reduced graphene oxide (rGO) DPV 0.014 μM 0.1–100 μM high anti-interference ability
dopamine MOF-5 @ MWCNTs MOF-5 (Zn-based) MWCNT DPV 0.0075 μM 0.1–60 μM synergistic effect for trace detection
glucose ZIF-67 @ MoS2/rGO ZIF-67 (Co-based) reduced graphene oxide (rGO) amperometry 1.39 μM up to ∼ 3 mM 12.62 μA mM–1 cm–2
heavy metals (Cu2+, Cd2+, Pb2+) UiO-66-NH2(Zr)/GO UiO-66-NH2 (Zr-based) graphene oxide (GO) DPASV 0.59 nM (Cu) 0.84 nM (Cd) Nanomolar range 12.38 μA μM–1 (for Pb2+)
bisphenol A GN - Cu-MOF Cu-MOF graphene (GN) DPV 35.0 nM 0.1–800 μM 0.89 μA μM–1 cm–2
methane (gas) ZIF-8/MWCNT ZIF-8 (Zn-based) MWCNT chemiresistive ∼0.22 ppb 10 ppb range high selectivity vs CO2/VOCs
nitrite MnMgFe-LDHs/ZIF-8/B,N-MWCNTs ZIF-8 (Zn-based) B,N-doped MWCNT amperometry 0.083 μM wide range enhanced conductivity via the ″island bridge″ structure
H2O2 Sn-MOF @ CNT Sn-MOF carbon nanotubes (CNT) amperometry N/A N/A high surface area and rapid electron transfer
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Conclusion

In conclusion, we present herein a platform material consisting of a highly porous and water-stable metal–organic framework (UiO-66-NH2) deposited on graphene, through solvothermal synthesis from its soluble precursors in the presence of suspended graphene platelets, resulting in a composite material effectively merging the high surface area and exceptional adsorption properties of the MOF, with the excellent electronic conductivity of graphene. This composite material was efficiently utilized in electrochemical sensing of soluble small molecules of anionic azo dyes, demonstrating a low detection limit (∼1 ppm) and a linear response with increasing concentration of the analyte. This approach can potentially be extended to electrochemical sensing of several other analytes, including soluble gases, small molecules, ions, or complexes, given that their molecular or ionic size allows them to diffuse into the pores of the MOF. The MOF@G platform exhibits high tolerance to a wide range of pH in aqueous solution, as well as being compatible with a wide range of organic solvents, limited only by the chemical stability of the MOF, and therefore can be utilized in aqueous and organic electrolytes for rapid, effective, and cost-efficient electrochemical sensing applications.

Experimental Section

All reagents and solvents were of commercial grade and used without further purification. Methyl orange was purchased from Cambrian Chemicals. Phenol red and Eriochrome Black T were purchased from SRL. ZrCl4 (>99.9%), 2-aminoterephthalic acid (99%), and N,N′-dimethylformamide (DMF) were purchased from Sigma-Aldrich. H2SO4 (ACS grade) and graphene were purchased from Fisher Scientific (surface area ∼450 m2/g). Synthesis of the UiO-66-NH2@G was conducted as outlined earlier.

UV–vis spectra were acquired on a Thermo Scientific Evolution-600 spectrophotometer. Surface area measurements were conducted on a Micromeritics ASAP 2020 using N2 (AirLiquide 99.999%) at a 77 K bath temperature. FTIR spectra were recorded on a Thermo Scientific iS-10 spectrophotometer. Electrochemical measurements were conducted on a Bio-Logic SP-50 potentiostat/galvanostat in a three-electrode setup utilizing Ag/AgCl (3.5 M KCl) as the reference electrode (Hanna Instruments), a graphite rod as the counter electrode, and a glassy carbon electrode (ALS Instruments, Japan) as the working electrode.

Acknowledgments

We acknowledge the financial support of the Academy of Scientific Research and Technology, Egypt (ASRT, P2P grant)

The authors declare no competing financial interest.

References

  1. Magar H. S., Fayez M., Febbraio F., Hassan R. Y. A.. Esterase-2 mutant-based nanostructured amperometric biosensors for the selective determination of paraoxon (Neurotoxin) Anal. Biochem. 2025;698:115751. doi: 10.1016/j.ab.2024.115751. [DOI] [PubMed] [Google Scholar]
  2. Hassan R. Y. A.. Advances in Electrochemical Nano-Biosensors for Biomedical and Environmental Applications: From Current Work to Future Perspectives. Sensors. 2022;22:7539. doi: 10.3390/s22197539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Safy M. E. A., Amin M., Haikal R. R., Elshazly B., Wang J., Wang Y., Wöll C., Alkordi M. H.. Probing the Water Stability Limits and Degradation Pathways of Metal–Organic Frameworks. Chem. – A Eur. J. 2020;26(31):7109–7117. doi: 10.1002/chem.202000207. [DOI] [PubMed] [Google Scholar]
  4. El-Mehalmey W. A., Ibrahim A. H., Abugable A. A., Hassan M. H., Haikal R. R., Karakalos S. G., Zaki O., Alkordi M. H.. Metal–organic framework@silica as a stationary phase sorbent for rapid and cost-effective removal of hexavalent chromium. J. Mater. Chem. A. 2018;6(6):2742–2751. doi: 10.1039/C7TA08281A. [DOI] [Google Scholar]
  5. Ma T., Li H., Ma J.-G., Cheng P.. Application of MOF-based materials in electrochemical sensing. Dalton Trans. 2020;49(47):17121–17129. doi: 10.1039/D0DT03388J. [DOI] [PubMed] [Google Scholar]
  6. Gonçalves J. M., Martins P. R., Rocha D. P., Matias T. A., Julião M. S. S., Munoz R. A. A., Angnes L.. Recent trends and perspectives in electrochemical sensors based on MOF-derived materials. J. Mater. Chem. C. 2021;9(28):8718–8745. doi: 10.1039/D1TC02025K. [DOI] [Google Scholar]
  7. Safy M. E. A., Haikal R. R., Elshazly B., Hamdy A., Ali F., Maarouf A. A., Alkordi M. H.. Charge percolation in metal-organic framework (HKUST-1)–graphene nanocomposites. Appl. Mater. Today. 2020;19:100604. doi: 10.1016/j.apmt.2020.100604. [DOI] [Google Scholar]
  8. Hassan M. H., Haikal R. R., Alkordi M. H.. Synergistic compounding of carbon nanotubes and metal–organic frameworks for oxygen-evolving electrocatalysis. Mater. Adv. 2022;3(19):7212–7218. doi: 10.1039/D2MA00361A. [DOI] [Google Scholar]
  9. Ye T., Wang X., Wang L., Ren S., Yang L., Chen L.. Novel Electrochemical Sensor Based on One-Step Encapsulation of Metal–Organic Framework (MOF) for Simultaneous Detection of SARS-CoV and SARS-CoV-2. ACS Appl. Mater. Interfaces. 2024;16(43):59648–59661. doi: 10.1021/acsami.4c16975. [DOI] [PubMed] [Google Scholar]
  10. Gu J., Lang S., Jin Z., Wei T.. A Dual-Functional and Efficient MOF-5@MWCNTs Electrochemical Sensing Device for the Measurement of Trace-Level Acetaminophenol and Dopamine. Molecules. 2024;29(23):5534. doi: 10.3390/molecules29235534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Yücer S., Sarac B., Ciftci F.. 2D MOF structure, electrochemical biosensing in bioelectronic applications. npj 2D Mater. Appl. 2025;9(1):81. doi: 10.1038/s41699-025-00603-y. [DOI] [Google Scholar]
  12. Song J., Liu H., Zhao Z., Guo X., Liu C.-k., Griggs S., Marks A., Zhu Y., Law H. K.-w., McCulloch I., Yan F.. 2D metal-organic frameworks for ultraflexible electrochemical transistors with high transconductance and fast response speeds. Sci. Adv. 2023;9(2):eadd9627. doi: 10.1126/sciadv.add9627. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hassan M. H., Haikal R. R., Hashem T., Rinck J., Koeniger F., Thissen P., Stefan H., Wöll C., Alkordi M. H.. Electrically Conductive, Monolithic Metal–Organic Framework–Graphene (MOF@G) Composite Coatings. ACS Appl. Mater. Interfaces. 2019;11(6):6442–6447. doi: 10.1021/acsami.8b20951. [DOI] [PubMed] [Google Scholar]
  14. Hassan M. H., Alkordi M. H., Hassanien A.. Probing the conductivity of metal-organic framework-graphene nanocomposite. Mater. Lett. 2019;246:13–16. doi: 10.1016/j.matlet.2019.02.124. [DOI] [Google Scholar]
  15. Hassan M. H., Soliman A. B., Elmehelmey W. A., Abugable A. A., Karakalos S. G., Elbahri M., Hassanien A., Alkordi M. H.. A Ni-loaded, metal–organic framework–graphene composite as a precursor for in situ electrochemical deposition of a highly active and durable water oxidation nanocatalyst. Chem. Commun. 2019;55(1):31–34. doi: 10.1039/C8CC07120A. [DOI] [PubMed] [Google Scholar]
  16. Begum S., Haikal R. R., Ibrahim A. H., Safy M. A. E., Tsotsalas M., Alkordi M. H.. Flash synthesis for conformal monolithic coatings of the Zr-based metal-organic framework (UiO-66-NH2) on non-modified surfaces: Applications in thin-film electrode systems. Surf. Interfaces. 2020;20:100587. doi: 10.1016/j.surfin.2020.100587. [DOI] [Google Scholar]
  17. Zhou Z., Mukherjee S., Hou S., Li W., Elsner M., Fischer R. A.. Porphyrinic MOF Film for Multifaceted Electrochemical Sensing. Angew. Chem., Int. Ed. 2021;60(37):20551–20557. doi: 10.1002/anie.202107860. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Chen X., Wang X., Fang D.. A review on C1s XPS-spectra for some kinds of carbon materials. Fullerenes, Nanotubes Carbon Nanostruct. 2020;28(12):1048–1058. doi: 10.1080/1536383X.2020.1794851. [DOI] [Google Scholar]
  19. Yamada Y., Kim J., Matsuo S., Sato S.. Nitrogen-containing graphene analyzed by X-ray photoelectron spectroscopy. Carbon. 2014;70:59–74. doi: 10.1016/j.carbon.2013.12.061. [DOI] [Google Scholar]
  20. Kandiah M., Nilsen M. H., Usseglio S., Jakobsen S., Olsbye U., Tilset M., Larabi C., Quadrelli E. A., Bonino F., Lillerud K. P.. Synthesis and Stability of Tagged UiO-66 Zr-MOFs. Chem. Mater. 2010;22(24):6632–6640. doi: 10.1021/cm102601v. [DOI] [Google Scholar]
  21. Hani A., Haikal R. R., El-Mehalmey W. A., Safwat Y., Alkordi M. H.. Durable and recyclable MOF@polycaprolactone mixed-matrix membranes with hierarchical porosity for wastewater treatment. Nanoscale. 2023;15(48):19617–19628. doi: 10.1039/D3NR04044E. [DOI] [PubMed] [Google Scholar]
  22. Yan R., Zhao Y., Geng H., Yan M., Wang J., Han S.. Electrochemical Sensor Capable of Enhancing Dopamine Sensitivity Based on Micron-Sized Metal–Organic Frameworks. Biosensors. 2025;15(6):348. doi: 10.3390/bios15060348. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Fan Q., Li X., Dong H., Ni Z., Hu T.. ZIF-67 Anchored on MoS2/rGO Heterostructure for Non-Enzymatic and Visible-Light-Sensitive Photoelectrochemical Biosensing. Biosensors. 2024;14(1):38. doi: 10.3390/bios14010038. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Li Z., Zhang X., Luo Y., Li Q., Qin Y., Wang G., Yang S., Liu Z.. An electrochemical sensor based on the composite UiO-66-NH2/rGO for trace detection of Pb­(II) and Cu­(II) Chem. Phys. Lett. 2023;830:140825. doi: 10.1016/j.cplett.2023.140825. [DOI] [Google Scholar]
  25. Ponnada S., Gorle D. B., Kiai M. S., Raju C. V., Faraji M., Sharma R. K., Nowduri A.. Understanding the endocrine disruptor and determination of bisphenol A by functional Cu-BTABB-MOF/rGO composite as facile rapid electrochemical sensor: an experimental and DFT investigation. Anal. Methods. 2022;14(5):560–573. doi: 10.1039/D1AY02150H. [DOI] [PubMed] [Google Scholar]
  26. Homayoonnia S., Phani A., Kim S.. MOF/MWCNT–Nanocomposite Manipulates High Selectivity to Gas via Different Adsorption Sites with Varying Electron Affinity: A Study in Methane Detection in Parts-per-Billion. ACS Sens. 2022;7(12):3846–3856. doi: 10.1021/acssensors.2c01796. [DOI] [PubMed] [Google Scholar]
  27. Du X., Han T., Jin B., Meng L.-Y., Han L.-H.. MnMgFe-LDHs/ZIF-8/B, N-WMCNTs nanocomposites for efficient electrochemical detection of nitrite and heavy metal ions. Carbon Lett. 2025;35(5):2287–2297. doi: 10.1007/s42823-025-00922-6. [DOI] [Google Scholar]
  28. Rani S., Sharma B., Malhotra R., Kumar S., Varma R. S., Dilbaghi N.. Sn-MOF@CNT nanocomposite: An efficient electrochemical sensor for detection of hydrogen peroxide. Environ. Res. 2020;191:110005. doi: 10.1016/j.envres.2020.110005. [DOI] [PubMed] [Google Scholar]
  29. Hashem T., Sanchez E. P. V., Bogdanova E., Ugodchikova A., Mohamed A., Schwotzer M., Alkordi M. H., Wöll C.. Stability of Monolithic MOF Thin Films in Acidic and Alkaline Aqueous Media. Membranes. 2021;11(3):207. doi: 10.3390/membranes11030207. [DOI] [PMC free article] [PubMed] [Google Scholar]

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