生物材料和医疗应用

Biosensors in Various Fields

Toshiharu Shinoka

Biosensors are the devices which are used to analyze the biological materials. Biosensors consist of a bioreceptor (it is also a biological material like enzyme, cell, cell organelle, tissue, nucleic acid, antibody, protein) which react with the analyte or sample and produces an eوٴect Нe eوٴect may be release of gases like oxygen or ammonia or change in the concentrations of protons or heat emission or absorption or other mechanisms. Нe eوٴect is measured, DmplLfied and displayed by a biotransducer. For example, the most commonly used and commercially available biosensor is blood glucose biosensor. It contains the immobilized enzyme glucose oxidase (bioreceptor) which breaks down the glucose (whose concentration is to be measured) present in the blood sample. In the reaction glucose oxidase reduces FAD to form FADH2 , which is further oxidized by the electrode in the sensor. Due the transfer of electrons a current is produced (eوٴect) which is detected, DmplLfied and displayed by the transducer. Нe amount of current produced is proportional to the amount of glucose present in the blood sample. Clark and Lyons in 1962 invented the first biosensor to measure glucose in samples. Нere are many glucose biosensors evolved with dLوٴerent transducers of which fluorescent glucose biosensor is used now-a-days