Boosting and Activating NIR-IIb Luminescence of Ag₂Te Quantum Dots with a Molecular Trigger

Abstract

Near-infrared (NIR) excited and NIR-IIb emissive Ag2Te quantum dots (QDs) display significant advantages in luminescence bioimaging and biosensing due to their unique photophysical properties. However, the poor luminescence intensity and limited strategy for constructing activatable probes severely restrict the wide bioapplications of Ag2Te QDs. Herein, we proposed a NIR dye-sensitization strategy to solve these two problems. First, we used IR-780 as the antenna for Ag2Te QDs to improve the ability of harvesting excitation light, obtaining 21-fold luminescence enhancement at 1620 nm under an 808 nm laser irradiation. Subsequently, by further functionalizing the heptamethine cyanine with a recognition unit of glutathione (GSH), Cy-GSH with target-triggered emission was yielded, which served as the potential sensitizer for Ag2Te QDs to fabricate an activatable ratiometric NIR-IIb nanoprobe for visualizing GSH in vivo with high contrast. This new strategy is expected as a powerful tool to promote the bioapplication of NIR-IIb QDs in the future.

Ligand-protected nanocluster-mediated photoswitchable fluorescent nanoprobes towards dual-color cellular imaging

“…1B). 46 In particular, 1,2-distearoyl-sn-glycero-3phosphoethanolamine with conjugated methoxyl poly(ethylene glycol) (DSPE-mPEG) was selected as the selfassembling reagent to form NPs with reasonable aqueous solubility. 47,48 The transmission electron microscopy (TEM) images showed that the resulting DPF NPs are well-dispersed with an average diameter of 35 ± 7 nm (Fig.…”

Activatable Probes for Ratiometric Imaging of Endogenous BiomarkersIn Vivo

“…For example, Liu et al designed a ratiometric FL probe (QDs@Cy-GSH) consisting of organic dyes Cy-GSH, DSPE-PEG, and Ag 2 Te quantum dots (QDs) for GSH detection. 404 The FL signal of QDs@Cy-GSH was enhanced at 1620 nm under 808 nm laser excitation upon incubation with GSH, while the FL signal remained unchanged at 980 nm. This resulted in an increased FL signal ratio (I 808ex /I 980ex ) as the concentration of GSH increased.…”

Ultra‐Broadband Photoluminescent Carbon Dots Synthesized by Laser‐Induced Thermal Shock

“…[40][41][42] Emission in NIR-II window (1100-1600 nm) is commonly covered by semiconductor quantum dots, such as PbS, or silver-based QDs such as AgTe or AgSe. [43][44][45][46][47] The CDs reported in this paper cover the whole spectrum from 400 to 1600 nm. The summarizing diagram is presented in Figure 4b.…”