Green synthesis and optimization of zinc oxide quantum dots using the Box–Behnken design, with anticancer activity against the MCF-7 cell line

Abstract

A green strategy and cost-effective approach was adapted to prepare Zinc oxide quantum dots (ZnO-QDs) for biomedical applications. The prepared ZnO-QDs may hold great promise as sensing scanners for diagnostics and therapy, as demonstrated in our current study. Zinc Sulphate, Azadirachta indica, and Catharanthus roseus leaves extract were used to synthesis a novel natural Zinc oxide bionanocomposite (ZnO-BC) and used as a precursor to prepare ZnO-QDs by microwave-assisted technique. The ZnO-BC was characterized by SEM-EDX, FTIR, XRD, Zeta potential and particle size analysis. The optical properties of QDs were investigated using UV and PL spectrophotometers. Experimental factors like the concentrations of ZnO-NPs, C. roseus and A. verawere evaluated using Box-Behnken design (BBD). MTT and haemolysis assay was performed using ZnO-BC and ZnO-QDs. Maximum absorbance observed at optimized values of 0.5% ZnO-NPs, 1g A.vera gel and 0.5ml C.roseus leaf extract of ZnO-QDs against BBD. There was decreased viability rate, ranging from 60-15% for 0.5mg/ml ZnO-BC and 45-5% for 5 mg/ml ZnO-QDs which revealed a tenfold decrease in cell viability with less concentration scale for 5mg/ml of ZnO-QDs when compared with that of 0.5 mg/ml ZnO-BC. Also, hemolysis test shows that the hemolysis ratio was below 0.5%, indicating non-haemolysis of ZnO-QDs. cellular morphology by results was supported by phase-contrast microscopy images. A good biocompatibility and high anticancer activity was noticed for ZnO-QDs when compared to ZnO-BC and provide versatile applications in the eld of Nano biomedicine.