In this study, microwave-assisted synthesized nitrogen and sulfur co-doped carbon dots (N-S-CDs) were used Hg2+ ions, cysteine and histidine sensor. The optimum pH was 7 and detection limit and linear range were 8 nM and 0.01- 50 µM, respectively. Fluorescence of N-S-CDs-Hg2+ system was recovered after addition of cysteine and histidine and this effect was used for the determination of these amino acids. The fluorescence recovery of the N-S-CDs–Hg2+ (25 µM) system was linearly increased with increasing the concentration of cysteine or histidine from 5 to 50 µM and LODs were 0.4 µM and 0.6 µM for cysteine and histidine, respectively. Simple and green synthesis, solubility in water, no need to any organic solvent and very fast response time were good properties of the new sensor.
