Zinc oxide nanoparticles (ZnO NPs) were prepared by a simple, convenient, and cost‐effective wet chemical method using the biopolymer starch. The prepared ZnO NPs were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX), Fourier transform infrared (FT‐IR), and UV‐visible spectroscopic techniques. The average crystallite size calculated from XRD data using the Debye–Scherer equation was found to be 15 nm. The electrochemical behavior of caffeine (CAF) was studied using a glassy carbon electrode (GCE) modified with zinc oxide nanoparticles by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Compared to unmodified GCE, ZnO NPs‐modified GCE (ZnO NPs MGCE) exhibited excellent electrocatalytic activity towards CAF oxidation, which was evident from the increase in the peak current and decrease in the peak potential. Electrochemical impedance study suggested that the charge‐transfer capacity of GCE was significantly enhanced by ZnO NPs. The linear response of the peak current on the concentrations of CAF was in the range 2–100 μM. The detection limit was found to be 0.038 μM. The proposed sensor was successfully employed for the determination of CAF in commercial beverage samples.
The simultaneous electroanalysis of acetaminophen (AC), guanine (G) and adenine (A) was successfully achieved on the zinc sulphide nanoparticles-modified carbon paste electrode (ZnS NPs/CPE) in phosphate buffer solution (PBS).
Molecular interaction studies between nanoparticles (NPs) and biomolecules are of great importance in the field of nanomedicine as they affect many physiological processes. Therefore, the interaction of zinc sulphide nanoparticles (ZnS NPs) with calf thymus deoxyribonucleic acid (CT DNA) and its significance was analyzed using ultraviolet (UV)–visible light, fluorescence, circular dichroism (CD), zeta potential, viscometry, electrochemical, and polymerase chain reaction methods. Fluorescence quenching analysis revealed that the fluorescence of ZnS NPs was quenched using CT DNA through a static quenching mechanism. The negative values of thermodynamic parameters (ΔG, ΔH, and ΔS) showed that the binding process was spontaneous, exothermic, and van der Waals or hydrogen bonding plays an important role in the interaction of ZnS NPs with CT DNA. Thermal melting (Tm) studies indicated a decrease in the Tm of CT DNA, suggesting the destabilization of CT DNA upon interaction with ZnS NPs. In addition, the results obtained from competitive binding, zeta potential, CD, and viscometry measurements showed that the interaction of ZnS NPs with CT DNA is through groove binding. Electrochemical analysis further confirmed the observed results from various spectroscopic and other related studies, in which decrease in the redox peak current along with changes in peak potential (CV) and increase in the electrical resistance (EIS) indicated the interaction between ZnS NPs and CT DNA. Furthermore, PCR analysis using DNA polymerase revealed the potential of ZnS NPs to inhibit DNA replication in vitro. ZnS NP–CT DNA interaction studies can be explored to define new horizons in biomedical applications of ZnS NPs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.