Table 4.

CNP-based PAI. Each piece of research is classified by CNP types, modification, abbreviation, theragnosis multimodalities, PA signal enhancement, novelties, maximum cytotoxicity concentration, and test species. HER2, epidermal growth factor receptor 2; HPPA, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-α; PS, protamine sulfate.

Types	Materials Modification	Multimodalities	PA Enhancement (Fold/Control)	Novelties	Cytocompatible Concentration	Test Species	Ref.
CD	Porphyrin and Cetuximab	PDT	N/A	Water stability, strong UV–vis and NIR abruption, and deep tissue penetration with high spatial resolution	≤100 μg/mL	HCC827, H23, MDA-MB-231, HBL-100, MDA-MB-231-mouse	[165]
	BSA–Cu2+–Gd3+ complex and HPPH	FL, MRI, PTT, PDT	N/A	In vivo mouse toxicity evaluation and decreased intracellular ROS generation	≤200 μg/mL	A549-BALB/c nude	[166]
	Mn and NCD	FL, PTT	N/A	Long emission wavelength and low hemolysis	≤1000 μg/mL	4T1-BALB/c mice	[170]
CND	AuNR and silica	FL, PDT, PTT	N/A	Chemical stability in a physiological environment and prevent absolute quenching of the FL	≤100 μg/mL	B16-F0 and B16-F0-nude	[171]
	Nitrogen	PTT	2/AuNR at water	Photostability, biodegradability, and SLN visualization	N/A	BALB/c nude	[184]
CNS	glucose	PTT	2.5/preinjection at mouse tumor	First investigation of CNS as PAI probe and controllable size of fabricated CNS	≤320 μg/mL	PC-3M-IE8, 4T1 and 4T1-nude	[175]
CNP	Honey, polysolvate, and PEG	N/A	N/A	One-pot green synthesis, markedly small probe for SLN imaging, rapid clearance properties, and rapid signal enhancement	N/A	Nude	[176]
ND	HA, PS, Cur, and IR780	FL, PTT, PDT	In vivo mouse tumor	Uniform size, high drug-loading ability, excellent colloidal stability, decreased hemolysis, and in vivo mouse toxicity evaluation	≤100 μg/mL	MDA-MB-231 and MDA-MB-231-mouse	[183]