ABSTRACT
The development of eco-friendly chemicals and material-based electrode systems with a reduced carbon footprint is a novel initiative for future technological applications. While electrochemical systems based on plant phytochemicals meet the requirements, comprehending the fundamental electron-transfer reactions and preparing stable surface-confined redox systems pose significant research challenges. In this study, we have demonstrated an in situ electrochemical reaction-assisted entrapment of redox-active betanin molecular species from native beetroot plants on a carbon black-modified glassy carbon surface (GCE/CB@Betn-Redox, where Betn-Redox stands for redox-active betanin molecular species) in a pH 2.2 KCl-HCl solution. In general, direct access to native plant phytochemicals is a formidable task due to the matrix effect. Isolating the desired phytochemicals necessitates a series of time-consuming chemical separation steps. Unlike previous literature reports on the unstable nature of Betn, GCE/CB@Betn-Redox exhibited a stable and well-defined proton-coupled electron-transfer peak at an apparent electrode potential, Eo' = 0.4 V vs Ag/AgCl, with a surface-excess value of 17.02 × 10-9 mol cm-2. Using several physicochemical techniques (transmission electron microscopy (TEM), Fourier-transform infrared (FTIR), and Raman), molecular techniques (UPLC), and electrochemical methods (in situ electrochemical quartz crystal microbalance (EQCM) and scanning electrochemical microscopy (SECM)), we have demonstrated the biomimicking electron-transfer functionality of CB@Betn-Redox. The unique feature of CB@Betn-Redox is its nonmediated effect on common biochemicals. This advantage makes it an interesting option for use as a selective pH sensor system without the complications of voltage drift that occur with the mediated oxidation/reduction functionality. We have successfully demonstrated highly selective and stable voltammetric and potentiometric pH sensor applications with practical real samples.
ABSTRACT
Nanobiotechnology is a unique class of multiphase and recently become a branch of contemporary science and a paradigm shift in material research. One of the two main problems facing the field of nanomaterial synthesis is the discovery of new natural resources for the biological production of metal nanoparticles and the absence of knowledge about the chemical composition of bio-source required for synthesis and the chemical process or mechanism behind the production of metal nanoparticles presents the second difficulty. We reported template-free green synthesized copper oxide nanoparticles using Tribulus terrestris seed natural extract without any isolation process. XRD, TEM, SEM, UV-Vis, DLS, zeta potential, and BET evaluated the synthesized metal nanoparticle. The TEM analysis confirmed that the CuO NPs are well dispersed and almost round in shape with an average size of 58 nm. EDAX confirms that copper is the prominent metal present in the nanomaterial. The greener fabricated copper oxide nanoparticle was employed to degrade methyl orange dye, almost 84% of methyl orange was degraded within 120 min. The outcomes demonstrated the nanomaterial's effective breakdown of contaminants, highlighting their potential for environmental rehabilitation. The electrochemical investigation of the CuO NPs was utilized for supercapacitor application. An appreciable value of specific capacitance is 369 F/g specific capacitances with 96.4% capacitance retention after 6000 cycles. Overall, the results of the current study show that the biologically produced copper oxide nanoparticles have intriguing uses as photocatalysts for treating water contaminants and are suitable for energy storage devices.