The research of applied biosensors is an interdisciplinary subject, which includes modern biotechnology, electronics, biology and other disciplines, and is a high-tech product. In the medical industry, the application of biosensors in many aspects (fermentation engineering, environmental monitoring, military, biosensors) has great potential. The application of sensors in medicine has also grown rapidly, playing a vital role in the development of medicine, especially in the research of microorganisms.

Biosensor is a device that changes biological substances and their concentration into electrical signals. Enzymes, antigens, antibodies, nucleic acids, cells, bacteria, immobilized sensitive materials, such as substances that recognize elements, pass through appropriate devices of physical and chemical sensors (such as diodes, piezoelectric crystals, etc.), and finally analyze the data through signal amplification devices or systems.

The substance is detected in the biosensitive membrane, and then chemically reacts through molecular recognition. The analyte sensitive membrane sensor in the sample (such as glycoprotein of exolectin, nucleic acid and its complementary fragment, etc.) reacts to produce certain changes in physical signals (such as light, heat, density, volume, which are amplified by the instrument and displayed and recorded. The corresponding signals such as sound are converted into processable or variable electrical signals, and finally the current or voltage value is directly measured. The amount or concentration of the substance being measured is thus obtained by calculation.

Compared with other sensors, biosensors have many advantages: small size, low production cost, certain anti-interference ability, and recyclable. The principle is: substance to be measured → molecular recognition element → electrical signal (light signal) arrow → signal amplification → data processing.