Aqueous synthesis and characterization of glutathione-stabilized β-HgS nanocrystals with near-infrared photoluminescence

► A simple and green aqueous route to NIR-emitting GSH-stabilized β-HgS NCs. ► The emission peak of β-HgS NCs shifted in a wide NIR region from 775 to 1041 nm. ► Enhanced emission efficiency and improved stability of GSH-capped β-HgS NCs.