Biological sensors are analytical devices that detect specific biological molecules or substances, such as proteins, enzymes, antibodies, or nucleic acids. These sensors are designed to provide real-time, accurate, and sensitive measurements of biological markers in various samples, including blood, urine, saliva, and tissue. Biological sensors are widely used in medical diagnostics, environmental monitoring, food safety, and drug development. They offer the advantages of rapid detection, high specificity, and low cost compared to traditional laboratory-based techniques, making them versatile tools for a wide range of applications.