Novel Potentiometric Non-Enzymatic Ascorbic Acid Sensor Based on Molybdenum Oxide Film and Copper Nanoparticles
Jung-Chuan Chou, Kun-Tse Lee, Chih-Hsien Lai, Po‐Yu Kuo, Yu–Hsun Nien, Yu-Hao Huang, Zhi-Xuan Kang
Abstract
In this study, we prepared a non-enzymatic potentiometric ascorbic acid sensor based on molybdenum oxide (MoO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) and copper nanoparticles (CuNPs). Also, we prepared a potentiometric sensor by monitoring the voltage change between the sensor and ascorbic acid, and proposed the reaction mechanism between molybdenum oxide and ascorbic acid. It is relatively rare in the field of non-enzymatic ascorbic acid sensors. Molybdenum oxide is a relatively new material applied in ascorbic acid sensors. The application of molybdenum oxide film and copper nanoparticles to ascorbic acid sensors is a new research direction. We employed screen printing technology to prepare reference electrodes and conductive wires on the polyethylene terephthalate (PET) substrate, and we also used epoxy for packaging. In the ascorbic acid concentration range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.81 ~\mu \text{M}$ </tex-math></inline-formula> -2 mM, we measured the characteristics of sensors with the voltage-time (V-T) measurement system, namely the average sensitivity, linearity, response time, interference effects, limit of detection (LOD), and temperature effects. The performance of the ascorbic acid sensor was significantly improved by the modification of CuNPs.