Biological devices that transform analyte concentration in a sample into quantifiable signals and aid in interpretation
are known as biosensor. Its high precision and speed are advantages. Numerous biosensor kinds are employed in
numerous fields. These biosensors are based on enzymes, nucleic acids, electrochemistry, and optics. Each of them
may consist of several parts and functions. Biosensors are particularly useful in the pharmaceutical, food, defense,
environmental, and agricultural industries, as well as in the early identification of diseases. Biosensors are widely
used in industrial processing and monitoring, environmental pollution management, veterinary and agricultural
applications, clinical analysis, and general health-care monitoring. Biosensor technology has promise for prompt
and precise identification, trustworthy cancer cell imaging, monitoring of angiogenesis and cancer spread, and the
capacity to determine the effectiveness of anticancer chemotherapy agents. Biosensors have increased worldwide
and have attracted the attention of scientists. In this study, the classification of biosensors, application areas,
characterization, studies on biosensors, and technologies developed and applied for the future are mentioned.