Thermal treatment of hair for the synthesis of sustainable carbon quantum dots and the applications for sensing Hg2+

A facile, simple and low-cost approach for synthesizing highly fluorescent carbon quantum dots (CQDs) from thermal treatment of sustainable hair has been developed. The resultant CQDs exhibited strong blue emission with a quantum yield of 10.75%, excellent photostability and high stability in high salt conditions. As the fluorescence of CQDs can be efficiently quenched by Hg2+, the CQDs can be constructed as a nanosensor for Hg2+ with good sensitivity and selectivity. And as low as 10 nM Hg2+ can be successfully detected.