 Zinc oxide, ZNO, nanomaterials have become increasingly popular due to their unique properties, including high-surface area, biocompatibility, electrochemical activity, and non-toxicity. These properties make them ideal candidates for a variety of applications, including electronics, optoelectronics, sensing, and biomedical and environmental applications. In addition, ZNO nanomaterials exhibit excellent electrochemical activity and electron communication, making them suitable for use in electrochemical sensors. This review discusses recent advances in ZNO nanomaterial-based chemical sensors, focusing on the effects of size, morphology, composition, and operational parameters such as size, morphology, composition, and operational parameters such as size, morphology, composition, and operating conditions. This article was authored by Savita Chaudhary, Ahmad Umar, K.K. Bussan, and others.