Biosensors are devices that are both sensitive and compact, and they measure biomolecules (called analytes) using various chemical or biological reactions to generate multiple output signals. For several decades, biosensors have been used in the healthcare, food, and environmental monitoring industries. In the healthcare sector, biosensors are used for disease diagnosis and treatment, as well as in research labs. The basic components of a typical biosensor include: Analyte or substrate: The biomolecule to be identified, such as the IgG antibody, which can be detected using various biosensors.