PNNL

Abstract

Integrating multifunctional optical imaging and photothermal properties within a single nanosystem is needed for the current nanomedicine application. Amorphous quantum nanomaterials have aroused attention due to their unique properties. Here, amorphous silver sulfide quantum dots (Ag2S QDs) with tunable near-infrared (NIR) fluorescence and photothermal performance are designed and obtained by doping of Cu2+. Density functional theory (DFT) simulation show that introducing Cu ions into the structure of amorphous Ag2S QDs forms stronger Cu-S bonds than Ag-S bonds leading to red-shift of fluorescence and defect states improve nonradiative recombination, which enhances the photothermal performance of amorphous Ag2S QDs. Our results showed that the non-toxic Ag2-xCuxS QDs in deed exhibit red-shift fluorescence and enhanced photothermal conversion (44%). Based on the tuned optical properties, they efficiently killed Hepa 1-6 cells in vitro under 635 nm laser irradiation and cured tumor bearing-mice with a volume decrease of ~87% based on NIR fluorescence imaging guided photothermal therapy. This study demonstrates that amorphous Ag2-xCuxS QDs can serve as an efficient NIR fluorescence imaging guided photothermal therapy agent for anticancer.