A biosensor measures change or concentration of some biological agent. For decades, biosensors have been used in all areas of research, including drug development, health monitoring, food and water analysis, blood tests, and even warfare. Typically, these sensors have been primarily biological themselves, consisting of proteins and bacteria known to react with the desired analyte. Their biological composition made them inherently slow and often bulky and expensive. New advances in solid state biosensors promise to revolutionize the biosensing world. Inexpensive, tiny fiber optic and planar waveguides utilize the properties of light and evanescent waves to detect when an analyte has bonded to its surface. Several innovative methods of sensing have already been developed, including using surface plasmon resonance, grating couplers, and resonant mirrors. These technologies promise decreased drug development time, quick and inexpensive health and quality monitoring, and safer tools for the future battlefield.

Figure 1: A Fiber Optic Biosensor