A novelty self-assembly nanosensor based on bimetallic doped quantum dots and peptides for monitoring tyrosinase and herbicide

Construction of highly selective and sensitive nano-biosensor is of great interest in enzymes and herbicides detection. In this work, a probe for tyrosinase (TYR) and atrazine was developed through the fabrication of glutathione modified bimetallic doped quantum dots (GSH-Cu,Mn-doped ZnS QDs) and dendritic mesoporous silica nanoparticles (DMSNs) with the TYR specific-response peptides. The as-prepared GSH-Cu,Mn-doped ZnS QDs and the peptides were efficiently self-assembled on the surface of DMSNs, which provided a restricted area for the reaction between TYR and the peptides, and the inhibition reaction of atrazine to TYR. It ensured the timely and sensitive fluorescence changes of the QDs with the introduction of TYR and atrazine. The linear ranges were obtained for TYR of 0.06–2.96 U/mL and for atrazine of 0.007–0.24 μg/mL, with the limit of detection as 0.008 U/mL for TYR and 1.00 ng/mL for atrazine, respectively. The probe was used to detect TYR in human serum and atrazine in vegetable samples.