Charge-Neutral, Stable, Non-Cytotoxic, Near-Infrared SnS Aqueous Quantum Dots for High Signal-to-Noise-Ratio Biomedical Imaging.

ABSTRACT: We have synthesized charge-neutral, stable, non-cytotoxic, bright, near-infrared (NIR) SnS quantum dots (QDs) by first making Cysteamine-capped SnS QDs in glycerol under acidic conditions followed by lengthening the capping molecule with peptide bonds by reacting the capping molecules with glycine and subsequent heat treatment at 200°C for 4 hours. The obtained stable SnS QDs exhibited a band gap of 1.5 eV and a strong, narrow NIR emission peak at 830 nm with a quantum yield of 4.6%. The suspension could be stable for more than 1 month without aggregation or emission decay. The positively charged SnS QDs were further neutralized by 3-mercaptoproprionic acid (MPA) through electrostatic attraction. The MPA neutralized SnS QDs were shown to be non-cytotoxic at concentrations 6 times the typic

SUBMITTER: Han S 

PROVIDER: S-EPMC6219619 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature