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Electrochemical application has been widely used in the study of biosensors. Small biomolecules need a sensitive sensor, as the transducer that can relay the signal produced by biomolecule interactions. Therefore, we are improvising a sensor electrode to enhance electrochemical conductivity for the detection of small DNA molecule interaction. This work describes the enhanced electrochemical conductivity studies of copper nanowires/gold nanoparticles (CuNWs/AuNPs), using the screen-printed gold electrode (SPGE). The AuNPs were synthesized using the Turkevich method as well as characterized by the high-resolution transmission electron microscopy (HRTEM) and ultraviolet-visible (UV-Vis) analysis for the particle size and absorption nature, respectively. Further, the surface morphology and elemental analysis of a series of combinations of different ratios of CuNWs-AuNPs-modified SPGE were analyzed by field emission scanning electron microscopy (FESEM) combined with an energy dispersive X-ray (EDX). The results indicate that the nanocomposites of CuNWs-AuNPs have been randomly distributed and compacted on the surface of SPGE, with AuNPs filling the pores of CuNWs, thereby enhancing its electrochemical conductivity. The cyclic voltammetry (CV) method was used for the evaluation of SPGE performance, while the characterization of the electrochemical conductivity of the electrode modified with various concentrations of AuNPs, CuNWs, and different volumes of dithiopropionic acid (DTPA) has been conducted. Of the various parameters tested, the SPGE modified with a mixture of 5 mg/mL CuNWs and 0.25 mM AuNPs exhibited an efficient electrochemical conductivity of 20.3 µA. The effective surface area for the CuNWs-AuNPs-modified SPGE was enhanced by 2.3-fold compared with the unmodified SPGE, thereby conforming the presence of a large active biomolecule interaction area and enhanced electrochemical activity on the electrode surface, thus make it promising for biosensor application.

Aluminum-based metal matrix composites with single or multiple ceramic reinforcements are finding application in the aerospace and automobile industries. In this research work, novel AA7150-B4C (aluminium7150 alloy–Boron carbide) nanocomposites were successfully fabricated, through the liquid metallurgy route via stir casting method, with the incorporation of B4C nanoparticles with different weight percentages using a novel sequence of a vortex technique and a double stir casting process with ultrasonication. The formed composites have been thoroughly studied for microstructure refinement, nano-particulate distribution, and bonding with the matrix by making use of the optical microscopy (OM) and scanning electron microscopy (SEM) studies (respectively). In addition, the composites were analyzed for the density, porosity, and elemental composition. Further, the composites were tested for the investigation of mechanical properties, like micro-hardness and tensile strength, to investigate the influence of ultrasonic vibration on the arrangement of B4C nano-particulates. The analysis indicated that the mechanical properties of the AA7150-B4C nanocomposites in as-cast condition significantly improved with a gain of 57.7% in strength and 24.5% in hardness compared to the native AA7150 material.

The uncertainties in ZnO-mediated toxicity and particle stability in a biological system remain a challenge and mitigate against deployment as next-generation nanoparticles (NPs), especially in biomedical applications. With that perspective, the present study investigates the surface chemical properties of ZnO NPs coated with three different surfactant biomolecules, namely polyethylene glycol (PEG), cetyltrimethylammonium bromide (CTAB), and sodium dodecyl sulfate (SDS) to control the toxicity-induced potentials. On the testing of the surface-functionalized ZnO NPs, notable changes in the particle sizes, morphology, zeta potential, and hydrodynamic size compared to the pure ZnO NPs are observed. In addition, FTIR spectroscopy, TGA, XRD, XPS, and HRTEM analysis showed significant changes in the surface structures and surface functional groups of the three different ZnO NPs on surface functionalization. Following the physical characterization, the cell viability of rat liver BRL-3A-treated ZnO–PEG, ZnO–CTAB, and ZnO–SDS compared to pure ZnO NPs ( ZnO–CTAB > ZnO–PEG, i.e., anionic > cationic > non-ionic. Overall from the analysis, the study stresses the importance of having a suitable surface ligand for the ZnO NPs so as to use them in the biomedical sector.