The idea of using multiple biosensors based on enzyme inhibition analysis to measure toxic substances is also put forward. In this multiple biosensor, two kinds of sensors-pH-sensitive electronic transistor and temperature-sensitive thin film electrode, and three kinds of enzymes-urease, acetylcholinesterase and butyrylcholinesterase are used. The performance of the biosensor has been tested and the effect is good [23].
In addition to fermentation industry and environmental monitoring, biosensors are also widely used in food engineering, clinical medicine, military and military medicine, mainly used to determine various amino acids such as glucose, acetic acid, lactic acid, lactose, uric acid, urea, antibiotics and glutamic acid, as well as various carcinogens and mutagens.
Three. Discussion and prospect
Harold H.Weetal of the United States pointed out that the commercialization of biosensors should meet the following conditions: sufficient sensitivity and accuracy, easy operation, low price, easy mass production and quality monitoring in the production process. Among them, the low price determines whether the sensor is competitive in the market. Among all kinds of biosensors, microbial sensors have the greatest advantages of low cost, simple operation and simple equipment, so their market prospects are very huge and attractive. In contrast, enzyme biosensor is relatively expensive. However, microbial sensors also have their own shortcomings, the main disadvantage is that the selectivity is not good enough, which is caused by the existence of many enzymes in microbial cells. It is reported that adding special inhibitors can solve the selectivity problem of microbial electrodes. In addition, the method of microbial immobilization also needs further improvement. Firstly, we should ensure the activity of cells as much as possible, and secondly, the combination of cells and basement membrane should be firm to avoid cell loss. In addition, the long-term preservation of microbial membranes needs to be further improved, otherwise it will be difficult to realize large-scale commercialization.
In a word, commonly used microbial electrodes and enzyme electrodes have their own advantages in various applications. If it is easy to obtain stable, high activity and low cost free enzyme, enzyme electrode is the most ideal for users. On the contrary, if biocatalysis requires complex pathways, coenzyme, or enzymes that are not suitable for separation or instability, microbial electrodes are a more ideal choice. Other forms of biosensors are also booming and widely used. With the further improvement of immobilization technology and the deepening of people's understanding of organisms, biosensors will surely open up a new world in the market.