Ratiometric Electrochemical Determination of Ascorbic Acid Using a Copper Nanoparticle@Resin Nanosphere (CuNPs@RNS) Modified Glassy Carbon Electrode (GCE) by Differential Pulse Voltammetry (DPV)

AbstractAscorbic acid (AA) determination is of high importance in the diagnosis and treatment of diseases. Herein, we report a new ratiometric electrochemical sensor for ascorbic acid using a glassy carbon electrode (GCE) modified with a copper nanoparticle@resin nanosphere nanocomposite (CuNPs@RNS). The ratiometric strategy was established by immobilizing an internal reference (thionine) on the modified electrode using cyclic voltammetry (CV). The performance of the modified electrodes as well as the newly established ratiometric strategy was explored. The sensing platform had good electrocatalytic ability, reproducibility, and stability. In addition, the ratiometric strategy significantly improved the performance of electrochemical sensing with a wide linear range (0.0837 to 15.5 μM) and a low detection limit of 0.0279 μM under the optimal conditions. The original ratiometric electrochemical sensor was successfully applied to monitor ascorbic acid in tablets and urine. These results showed that the sensor provides a new strategy and broad prospects for biomolecular sensing with reliability and high sensitivity.Keywords: Ascorbic acidcopper nanoparticle@resin nanosphere (CuNPs@RNS) modified glassy carbon electrode (GCE)differential pulse voltammetry (DPV)ratiometric electrochemical sensorsthionine Disclosure statementThe authors declare that they have no known competing financial interests or personal relationships that influenced the work reported in this paper.CrediT authorship contribution statementAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Jie Zhang, Yulin Fu, and Lin Li. The first draft of the manuscript was written by Jie Zhang and all authors commented on subsequent versions of the manuscript. All authors read and approved the final manuscript.Additional informationFundingWe appreciate the financial support of the Natural Science Foundation of Guangxi, China (Grant Number 2021GXNSFBA196019), Guangxi Key Laboratory of Electrochemical and Magneto-Chemical Functional Materials (Grant Number EMFM20211107), and Youth Program of the National Natural Science Foundation of China (21903027).