Synthesis of CuxO nanoparticles using a customized 2-axial ultrasonic reaction chamber and their electrochemical sensing characteristics

Abstract

In this study, CuxO nanoparticles were synthesized with varying ultrasonic powers (20–80 W) using a customized two-axial ultrasonic chamber, and their electrochemical sensing of dopamine (DA) was evaluated. The two-axial ultrasonic chamber offers several advantages, including accelerating wave propagation into the reaction mixture, enhancing chemical reactivity, and facilitating a uniform particle formation process. The synthesized CuxO at lower ultrasonic power (20 W) showed a homogeneous elongated platelet-like morphology, which was broken and transformed into particulate morphologies at higher ultrasonic power (80 W). Morphological, compositional, and spectral studies confirmed primarily the formation of the CuO phase. Nitrogen adsorption/desorption isotherm results revealed that the specific surface area and pore volume increased from 22.36 to 35.95 m2/g and from 0.154 to 0.214 cm3/g, respectively, with increasing ultrasonic power from 20 to 80 W. The electrochemical impedance spectroscopy studies in the Fe2+/Fe3+ electrolyte demonstrated enhanced charge transfer characteristics of CuxO-modified electrodes. Cyclic voltammetry (CV) studies identified distinct Fe2+/Fe3+ redox peaks on CuxO-modified electrodes, and CuxO-80 W achieved a lower potential difference between the anodic and cathodic peaks, indicating its enhanced electrochemical activity. The electrochemical sensing ability of the DA molecule at varying concentrations in phosphate buffer saline showed a clear DA oxidation peak for CuxO-80 W-modified electrodes. The CV and chronoamperometry studies showed that the modified electrode can sense DA in a linear concentration range from 0.0125 to 0.50 mM, with a sensitivity of 646.3 μA mM−1 cm−2, a response time of 5 s, and a limit of detection of 0.20 μM.