A biosensor is a device that can detect biological molecules such as proteins, enzymes and antibodies and convert a biological response into a quantifiable and processable signal by converting it into an electrical signal. Biosensors are used for a variety of purposes including rapid testing, environmental monitoring and food safety. Biosensors are generally composed of two parts: a biological component, such as an enzyme or antibody, and a physical component, such as a transducer or detector. The biological component reacts with a target molecule and produces a signal, which is then detected by the physical component.

Biosensors are important for the development of rapid tests as they are able to detect molecules quickly and accurately, and the results can be used to guide a patient's treatment. Biosensors are also used in environmental monitoring to detect and measure pollutants in the environment or even in the context of food safety, in the detection of foodborne pathogens and contaminants.

The use of biosensors in the health area has allowed the rapid diagnosis and treatment of diseases, making health more efficient and economical. Biosensors are also being used to detect and monitor chronic conditions such as diabetes and heart disease. Furthermore, biosensors are being used in the development of new drugs, as they can detect the effects of a drug on a molecule or cell. The use of biosensors in healthcare is expected to increase in the future and continue to transform healthcare.