Chemical sensing refers to the process of detecting and measuring specific chemical substances in the environment. This technology is widely used in various fields, including environmental monitoring, healthcare, and industrial applications. Chemical sensors can identify gases, liquids, or even biological molecules, providing valuable information about the presence and concentration of these substances. These sensors often rely on specific reactions between the target chemical and the sensing material, which can produce measurable changes, such as electrical signals or color changes. Examples of chemical sensing devices include gas sensors, biosensors, and pH meters, each designed for particular applications and types of chemicals.