Fig. 1. Strategies for improving the chiral purity and fluorescence intensity of single-walled carbon nanotubes. (a) Chirality distribution of SWCNTs synthesized via Co-TUD-1 catalysis^[22]; (b) addition of a reducing agent enhances the fluorescence intensity of SWCNTs^[25]

Fig. 2. Characterization of NIR-IIb emitting CSQDs^[43]. (a) CSQD design scheme; (b) transmission electron microscope (TEM) and high resolution TEM images of synthesized PbS/CdS QDs; (c) HAADF-STEM images of PbS/CdS core/shell nanostructure

Fig. 3. Strategies for the use of RENPs for in vivo imaging. (a) Schematic diagram of PMH coating and polyethylene glycol treatment process for Er-RENPs^[45]; (b) schematic diagram of activatable NIR-II fluorescent probes based on LnNPs^[48]; (c) RZND nanoplatform for NIR-II imaging in MRSA infection model and NIR light-controlled antimicrobial therapy^[49]

Fig. 4. Strategies to enhance and modulate NIR-II fluorescence emission from AuNCs. (a) Scheme of the AuNCs AuMHA/TDT^[55]; (b) synthesis of Ln@AuNCs and their NIR-II photoluminescence changes upon ligand anchoring-mediated assembly and H₂S treatment^[56]; (c) scheme of NAC-AuNCs utilizing ONOO^- responsive aggregation for imaging acute kidney injury in mice^[57]

Fig. 5. Fluorescent probes of anthocyanins imaged in NIR-II.(a) Schematic diagram of the synthesis of FD-1080^[63]; (b) structural schematic of IR-783 conjugated to BSA^[64]; (c) synthetic route of LZ-1105^[66]; (d) normalized absorption and fluorescence intensity of LZ-1105 in PBS, demonstrating an absorbance peak at 1041 nm and an emission peak at 1105 nm, the fluorescent emission spectrum was obtained under 1064 nm laser excitation^[66]; (e) structure of FD-1080 and DMPC^[67]; (f) normalized absorption (solid lines) and emission (dashed line) of FD-1080 monomer and J-aggregates^[67]

Fig. 6. Strategies for the design of rhodamine fluorescent molecules. (a) Design concept of X-rhodamine dye^[68]; (b) synthesis of ESi5a-ESi5 and ESi5b-PEG^[69]; (c) chemical structures of PCP-BDP1, PCP-BDP2, Ph-BDP1, and Ph-BDP2, and fluorescence spectra of PCP-BDP2 in diluted dichloromethane solution, THF-water binary solvents, and the crystalline powder^[71]; (d) molecular structures of SW1 to SW8^[72]

Fig. 7. Modification strategies for coumarin and naphthylimide dyes in NIR-II. (a) Molecular design of coumarin-derived BioAIEgens with improved performances using"rotor-alicyclic"strategy^[73]; (b) schematic of the FDF dots design^[74]; (c) emission peaks of fluorescent groups from coumarin and its silicon substituted derivatives^[75]; (d) design strategy for naphthalimide-based probes and the precise regulation of the π-conjugated bridges bound to the recognition site alignment^[78]