CuO Nanoparticulate Modified Microelectrode for Neurotransmitters Detection by Fast-Scan Cyclic Voltammetry

Neurotransmitters are referred to as the body’s chemical messengers that play an important role in the central nervous system. Dopamine (DA) and acetylcholine (ACh) are some of the most significant neurotransmitters involved in motor control. Abnormality of neurotransmitters level can signal the trace of neurological diseases related to brain disorders such as Parkinson’s and depression [1].<br/>Nowadays, several techniques are used for neurotransmitters measurements fast-scan cyclic voltammetry (FSCV), which is the real-time monitoring of neurotransmitters in the brain. It has been used to identify and discriminate dopamine and acetylcholine from the interferents. Moreover, FSCV offers many advantages, including millisecond time, high resolution, moderate selectivity, and high sensitivity [2]. Metal oxide nanoparticles have appeared as talented sensors candidates, attributed to substantial reactive sites on the surface and enhanced electron transfer.<br/>This study aimed to investigate and modify the flexible microelectrode with copper oxide (CuO) as the electrochemical sensor for dopamine and acetylcholine detection. CuO nanoparticulate is relatively non-toxic, biocompatible, and exhibits a high electron transfer [3-4]. Metal oxide nanoparticles were synthesized by solution combustion technique. The microelectrodes were applied onto a flexible polyimide substrate with a diameter of 100 µm. Microelectrode for the electrochemical measurement has prepared by mixing metal oxide nanoparticles and MWCNTs and underwent hydrothermally.<br/>Electrochemical performance of CuO modified microelectrodes has been evaluated by fast-scan cyclic voltammetry and conducted in dopamine and choline acetate solution with a concentration between 0 to 100 mM. Cyclic voltammogram showed the peak current corresponding to the oxidation reaction of CuO for dopamine and acetylcholine at the applied potential of 0.26 and 0.18 V, respectively. The CuO modified microelectrode observed a linear response of dopamine and acetylcholine with a sensitivity of 2.30 and 4.07 nA/µMµm², respectively. The electrochemical performance exhibited a high sensitivity of CuO modified microelectrode expand more than two orders [5-6]. Furthermore, the CuO modified microelectrode showed a promising alternative approach for real-time detection.<br/><b>References</b><br/>[1] A.G. Zestos <i>et al.,</i> <i>International Journal of Electrochemistry</i>, 1-19, 2018.<br/>[2] P. Puthongkham and B.J. Venton <i>et al.,</i> Analyst, 145, 1087-1102, 2020.<br/>[3] S. Sundar, G. Venkatachalam <i>et al.,</i> <i>Nanomaterials(Basel)</i>, 8(10):823, 2018.<br/>[4] S. Reddy, B.E.K. Swamy <i>et al.,</i> Electrochimica Acta, 61, 78-86, 2012.<br/>[5] J. Bao, T. Huang <i>et al., Sensors and Actuators B: Chemical</i>, <i>279</i>, 95–101, 2019.<br/>[6] B. Li, Y. Zhou <i>et</i> <i>al.,</i> <i>Biosensors and Bioelectronics</i>, <i>67</i>, 121–128, 2015.