Biosensors are analytical devices that interpret biological information into a quantifiable signal. Biosensors differ from other popular analytical systems, such as high-performance liquid chromatography (HPLC), in that they are self-contained integrated devices. However, biosensors can be incorporated into larger analytical systems. There, they act as a receptor device that can selectively collect quantitative or semi-quantitative information.
Biosensors are made of five main components: a bioreceptor, an interface, a transducer element, computer software, and a user interface. The bioreceptor binds to the analyte selectively, and the interface is where a chosen biological event occurs that gives rise to the signal that is measured. The signal is measured by the transducer element. The transducer element, which in the case of electrochemical biosensors is an electrochemical transducer, turns the transducer signal into an electronic signal and amplifies it. The computer software converts the electronic signal into a physical parameter that can meaningfully be interpreted. This is then presented through the user interface to the operator.