Aqueous synthesis of high bright Ag2SeZnSe quantum dots with tunable near-infrared emission

Efficient aqueous synthetic methods for near-infrared quantum dots as bioimaging agents are urgently required. In this work, a simple and fast synthesis of highly luminescent, near-infrared Ag 2 Se quantum dots (QDs) in aqueous media is reported. The method avoids high temperature, pressure and organic solvents to directly generate water-dispersible Ag 2 Se QDs. The photoluminescence emission of Ag 2 Se QDs ranges from 835 to 940 nm by different Ag:Se molar ratio. Using the ZnSe as a shell, the quantum yield reaches up to 42%. The Ag 2 Se ZnSe QDs with high quantum yield, near-infrared and low cytotoxic could be used as good cell labels, showing great potential applications in bio-imaging.