Facile synthesis of β-lactoglobulin capped Ag₂S quantum dots for in vivo imaging in the second near-infrared biological window

Abstract

Effective in vivo fluorescence imaging for cancer screening and diagnostics requires bright and biocompatible fluorophores whose emission can effectively penetrate biological tissues. Recent studies have confirmed that the second near-infrared window (NIR-II, 1,000-1,400 nm) is the most sensitive spectral range for in vivo imaging due to ultralow tissue absorption and autofluorescence. We report herein a facile synthesis of Ag2S QD LG T LG biodistribution and reduces in vivoQDs exhibit superior photostablity and biocompatibility, making them a promising probe for in vivo NIR-II imaging.

Ultrasmall Pb:Ag2S Quantum Dots with Uniform Particle Size and Bright Tunable Fluorescence in the NIR‐II Window

“…Although various synthetic approaches had been applied to prepare Ag 2 S QDs, including tuning particle size, engineering surface ligands, coating shells etc., none of these Ag 2 S QDs had a PLQY that could compete with traditional Cd‐, Pb‐based QDs . The high Ag + ions' mobility in Ag 2 S crystal lattice, which causes abundant cation vacancies and crystal defects, is detrimental to photoluminescence efficiency of QDs and hard to be solved by routine synthetic methods.…”

Recent Advances of Low Biological Toxicity Ag2S QDs for Biomedical Application

“…This leads to a reduction in resonance energy transfer, which in turn leads to an increase in PL intensity with blue shift. Chen synthesized Ag 2 S QDs using β ‐lactoglobulin ( β ‐LG) as a biological template that emits at ≈1100 nm. NIR‐II Ag 2 S QDs prepared by biomolecules (e.g., peptides and proteins) as soft templates in the aqueous phase has been reported .…”

NIR Fluorescent Nanoprobes and Techniques for Brain Imaging

“…13.5). NIR-emitting Ag 2 S QDs [44][45][46][47][48][49][50][51][52][53][54][55][56][57], and PbS QDs [33][34][35][36][37][38][39][40][41][42][43] [45], (c) glutathione-capped PbS QDs [33], and (d) rare earth-doped nanoparticle [59] are semiconductor nanocrystals that have unique optical properties, such as sizedependent tunable emissions, narrow emission bands, high quantum yields, and high resistance to photobleaching. In 2010, Wang group first synthesized NIR-emitting Ag 2 S QDs for bioimaging by thermal decomposition of (C 2 H 5 ) 2 NCS 2 Ag [44].…”

“…During the past 5 years, several types of NIR fluorescent probes such as singlewalled carbon nanotubes (SWNTs) [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32], PbS QDs [33][34][35][36][37][38][39][40][41][42][43], Ag 2 S QDs [44][45][46][47][48][49][50][51][52][53][54][55][56][57], and rare earth-doped nanoparticles [58][59][60][61] have been developed for in vivo imaging in the 2nd NIR window. Recently, organic dye-based NIR nanoprobes with low toxicities have attracted much attention for deep-tissue imaging in the 2nd NIR window .…”