Ultraviolet/ultrasound-activated persulfate for degradation of drug by zinc selenide quantum dots: Catalysis and microbiology study.

In this study, wet chemical method used for ZnSe quantum dots (QDs) and characterized by, UV-vis, photoluminescence spectroscopy, X-ray diffraction and transmission electron microscopy. The crystallites size of ZnSe QDs was 4.0nm. The average diameters of ZnSe QDs were 3.0-5.3nm. Ritalin was degraded using the UV/ZnSe QDs/persulfate process. The several parameters investigated for the influence of Rtialin degradation were the temperature, the persulfate concentration, and the initial Ritalin concentration. The values of optimum parameters ware room temperature, concentration persulfate 5mmol/L and initial Ritalin concentration 0.09mmol/L. Comparative analyses showed the maximum degradation of Ritalin was found for ZnSe/persulfate under ultra-visible and ultra-sonic irradiation process. Comparative analysis showed the maximum degradation of Ritalin was found for ZnSe/persulfate under ultra-visible and ultra-sonic irradiation process. The values of first-order rate constants from degradation of Ritalin at 25°C were 0.96×10, 1.09×10, 1.59×10 and 2.19×10 for US/PS, UV/PS, ZnSe/US/PS and ZnSe/UV/PS system, respectively. The antibacterial activity evaluation against two bacterials, including Gram-positive bacteria Staphylococcus aureus (ATCC 43300), Bacillus megaterium (ATCC 14581) and Gram-negative bacteria Pseudomonas aeruginosa (ATCC 27853), Micrococcus luteus (ATCC 4698) was considered. It was found that the MIC values for the antibacterial assay in the presence of ZnSe QDs were around 0.30mM with 64.0, 66.0, 79.2, and 83.5% inhibition for the S. aureus, B. megaterium, P. aeruginosa and M. luteus bacterial strains, respectively. Then, results show that the ZnSe QDs have antibacterial activity.