Gram-Scale Synthesis of Hydrophilic PEI-Coated AgInS₂ Quantum Dots and Its Application in Hydrogen Peroxide/Glucose Detection and Cell Imaging

Assisted with polyethylenimine, 4.0 L of water-soluble AgInS 2 quantum dots (AIS QDs) were successfully synthesized in an electric pressure cooker. As-prepared QDs exhibit yellow emission with a photoluminescence (PL) quantum yield up to 32%. The QDs also show excellent water/buffer stability. The highly luminescent AIS QDs are used to explore their dual-functional behavior: detection of hydrogen peroxide (H 2 O 2 )/glucose and cell imaging. The amino-functionalized AIS QDs show high sensitivity and specificity for H 2 O 2 and glucose with detection limits of 0.42 and 0.90 μM, respectively. A linear correlation was established between PL intensity and concentration of H 2 O 2 in the ranges of 0.5–10 μM and 10–300 μM, while the linear ranges were 1–10 μM and 10–1000 μM for detection of glucose. The AIS QDs reveal negligible cytotoxicity on HeLa cells. Furthermore, the luminescence of AIS QDs gives the function of optical imaging.