 Biosensors have become crucial in drug discovery, biomedicine, food safety standards, defense, security, and environmental monitoring due to their ability to provide precise and powerful analytical tools using biological sensing elements as biosensors. Recent advances in biological techniques and instrumentation have increased the sensitive limit of biosensors while integrated approaches provide specific and sensitive biosensors with high regenerative potentials. Various types of biosensors ranging from nanomaterials, polymers to microbes have wider potential applications, and this review provides an overview of different types of biosensors being used for various biomedical and environmental applications with a future outlook of biosensor technology. This article was authored by Vineshvar Es, Sudakumari ECC, Balasubramanian ESENTHLKUMRN, and others.