Experimental evidence on RH-dependent crossover from an electronic to protonic conduction with an oscillatory behaviour

An oxide semiconductor changes its resistance with exposure of water molecules and is accepted to be governed by electronic and protonic conduction in low and high humid atmosphere, respectively, without any experimental evidences. Here, we report on the experimental evidence of a relative humidity (RH) dependent crossover, from an electronic to protonic conduction and its oscillatory behaviour in mesoporous SnO2. Interestingly, oscillatory conduction observed in the intermediate humidity range (70%-90% RH) lies in between two monotonic variations that substantiate the competitive adsorption and desorption processes of oxygen species and water molecules. In addition, we have shown that the conduction process can be tuned predominantly electronic or protonic by pre-and post-UV treatment. The conductance increases by 2-3 orders as the conduction changes from pure electronic to protonic, suggesting an insulator-to-metal like transition. Published by AIP Publishing

In Vitro Anticancer and Antibacterial Activity of Green Synthesized ZnO NPs Using Clitorea Ternatea Flower Extract: Inhibits MCF-7 Cell Proliferation Via Intrinsic Apoptotic Pathway

Abstract Herein, we report a strategy to synthesize zinc oxide nanoparticles (ZnO NPs) from Clitorea ternatea flower extract through green synthesis platform. The bioactive components in the C. ternatea flower extract acts as a stabilizing and capping agent, which enables the synthesis of ZnO NPs without the use of chemical reagents. Synthesis of of ZnO NPs through green platform was confirmed by analytical characterization techniques such as UV-Vis spectrophotometry, XRD, FTIR, DLS, Zeta potential, TEM, and EDX methods. The surface morphology and average size of ZnO NPs investigated through TEM and DLS results indicates rod shaped structure with average particle size of 84 nm. Green synthesized ZnO NPs shows excellent antibacterial, antibiofilm, and antioxidant activity which is dose-dependent. These ZnO NPs have cytotoxicity against breast cancer cells (MCF-7). The MTT test revealed a concentration-dependent inhibitory effect on MCF-7 cells, with IC50 being 12.1 g/ml, and their anticancer potential was detected utilizing live and dead cell assays LDH release, Ao/EtBr), DAPI, ROS, and caspase-3 activation assays. Finally, the findings of these results shows that ZnO NPs derived from Clitorea ternatea flower extract are highly potential candidates to treat bacterial infection and human breast cancer.</jats:p