Recent advances in the synthesis of ZnO-based electrochemical sensors

Until now, various composites based on zinc oxide (ZnO) have been investigated in electrochemical sensors. The physical and electrochemical properties of ZnO and its structure can improve the selectivity, sensitivity, and adaptability of nanocomposites. Therefore, the focus on the fabrication of cheap ZnO-based electrodes with affordable and easy transportability has increased. In addition, the electrochemical behavior is affected by the structure and morphology of the ZnO-based composite in detecting pollutants such as volatile organic compounds, heavy metals, and toxins. Furthermore, ZnO-based nanostructures are efficient in the fabrication of electrochemical sensors in the food industry, pharmaceutical analysis, and medical diagnostics. In this review, various techniques in the synthesis of ZnO-based electrodes and their effect on the particle size, shape, and morphology of compounds have been collected. Since the performance of chemical sensors has a direct relationship with the structure of the composite used in its electrode, it is necessary to discuss the new production methods, new concepts, strategies, and challenges. Additionally, new gains highlight recent developments and sensing of various analytes in the monitoring systems. These sensors have demonstrated a strong growth acceleration which could lead to the development of recent technologies. At last, an optimistic outlook is provided on the future of ZnO-based sensors and their challenges.