S doped silicon quantum dots with high quantum yield as a fluorescent sensor for determination of Fe3+ in water

Novel S-doped silicon quantum dots (S-SiQDs) were prepared by l-cysteine doped silicon quantum dots (SiQDs) for fluorescent detecting Fe3+ in water. The as-prepared S-SiQDs sensor with an average diameter of 4.77 nm possessed richness of –NH2, endowing good water solubility and strong blue fluorescence. The quantum yield (QY) of ~66% was abtained when S-SiQDs exited at 345 nm. The synergistic effect of electron transfer that the electron of –NH2 on S-SiQDs surface transfer to 3d unoccupied obrials of Fe3+, inner filter effectaccounted for fluorescence quenching. The probe possessed a relative wide liner range from 1 μmol/L to 20 μmol/L with the limit of detection (LOD) of 0.21 μmol/L to detecte Fe3+. The as-prepared S-SiQDs sensor could sensitively and selectively detect Fe3+ in real water samples with satisfied recoveries of 90%–106%, which presented its potential applicability in the environmental fields.