Preparation of ZnS:Ni/ZnS quantum dots with core/shell structure and application for detecting cefoperazone-sulbactam.

ZnS:Ni quantum dots (QDs) have been synthesized via a water-soluble route, which were coated by ZnS shell through surface modification to give ZnS:Ni/ZnS QDs. The QDs were characterized by atomic force microscope, X-ray diffraction, infrared spectrometry and fluorescent spectrometry. Then, a novel method for the determination of cefoperazone-sulbactam (CPZ-SBT) in aqueous solutions has been developed based on the enhancement of fluorescence of ZnS:Ni/ZnS QDs in the presence of CPZ-SBT. Under the optimal conditions, the enhanced fluorescence intensity (ΔF) was proportional to CPZ-SBT concentration in the range of 8.0×10(-6)-1.0×10(-4) g/L with a detection limit of 1.0×10(-7) g/L. The method was employed for the determination of CPZ-SBT in sample to give satisfactory result. Compared with others, this method was more sensitive, fast and simple with low limit detection.