A fluorescent and colorimetric probe for MoO42- based on sulfur quantum dots nanozyme

In this study, with the assistance of chitosan oligosaccharide, sulfur quantum dot (COS-S QDs) nanozyme were synthesized with excellent fluorescence and peroxidase activity. Since MoO42- can statically quench the fluorescence of COS-S QDs and inhibit the peroxidase activity of COS-S QDs, the fluorescence intensity at 435 nm and the absorbance value of TMB at 652 nm were both related to the concentration of MoO42-. The changes of relative fluorescence intensity and absorbance showed a good linear relationship with the concentration of MoO42-, and the detection limits were respectively 0.068 mM and 0.0052 mM. In addition, satisfactory results were also obtained by the use of this new method for the determination of MoO42- in toiletries and cigarettes, with the recovery range of 96∼105.5%.