Biosensors are designed to specifically detect and measure the presence or concentration of biological molecules, such as proteins, DNA, or glucose, through various sensing mechanisms.

Radioactive biosensors are not commonly used due to safety concerns associated with radiation exposure and disposal of radioactive materials.

Enzymatic biosensors utilize the catalytic activity of enzymes to convert a specific biological molecule into a detectable signal. The enzyme-substrate reaction generates a product that can be measured, either directly or indirectly.

Optical biosensors, particularly those based on FRET, utilize the transfer of energy between two fluorescent molecules to detect the presence or concentration of a target biological molecule.

Electrochemical biosensors offer high sensitivity and specificity, non-invasive operation, and rapid response times, making them suitable for various applications, including medical diagnostics and environmental monitoring.

Optical biosensors, such as DNA microarrays and next-generation sequencing platforms, are widely used for DNA sequencing by detecting the presence or absence of specific DNA sequences.

Aptamers are synthetic DNA or RNA molecules that can bind to specific target molecules with high affinity and specificity. They are often used in biosensors as recognition elements for detecting the presence of target molecules.

Optical biosensors based on SPR detect changes in the refractive index at a metal-dielectric interface caused by the binding of target molecules to the sensor surface.

Piezoelectric biosensors utilize the piezoelectric effect to detect mass changes associated with the binding of target molecules to the sensor surface.

Electrochemical biosensors, particularly those based on glucose oxidase, are widely used for non-invasive glucose monitoring in diabetic patients.

Biosensors play a crucial role in environmental monitoring by detecting pollutants in air and water, monitoring microbial contamination, and assessing soil quality.

Immunosensors utilize antibodies or antigens to specifically detect the presence of viruses and bacteria by exploiting the antigen-antibody binding interaction.

The development of biosensors faces challenges related to high production costs, achieving sufficient specificity and sensitivity, and ensuring stability and reproducibility of the sensing elements.

Electrochemical biosensors, particularly those based on stripping voltammetry, are widely used for detecting heavy metals in environmental samples due to their high sensitivity and ability to measure metal ions at low concentrations.

Biosensors have the potential to revolutionize healthcare by enabling early disease detection and diagnosis, facilitating personalized medicine and targeted therapies, and allowing continuous monitoring of vital parameters for improved patient care.