Chemical sensors are devices that detect and measure specific chemical substances in the environment. They work by responding to changes in chemical composition, often producing a measurable signal, such as an electrical current or a color change. These sensors are widely used in various fields, including environmental monitoring, healthcare, and industrial processes. The technology behind chemical sensors can vary, with some using electrochemical methods while others rely on optical techniques. Common applications include detecting pollutants in air or water, monitoring glucose levels in diabetes management, and ensuring safety in industrial settings by identifying hazardous gases.