What is immobilization of biosensors? What are the immobilization methods?

Biosensors are composed of two parts: the biosensitive element and the signal transducer. The selectivity of a biosensor mainly depends on the selection of the sensitive material, while the sensitivity is greatly related to the type of transducer and the immobilization technology of the biological components. Therefore, the development of immobilization technology is one of the key factors to improve the performance of sensors. For biosensors to show good performance, the immobilization technology should meet the following conditions: (1) the immobilized biocomponents can still maintain good biological activity; (2) the biofilm must be in close contact with the transducer, and can be adapted to a variety of testing environments; (3) the immobilized layer should have good stability and durability; (4) reduce the interaction of the biocomponents in the biofilm in order to maintain its original high selectivity. Selectivity. In order to develop inexpensive, highly sensitive and selective biosensors, immobilization technology has become the goal of researchers. After nearly 20 years of unremitting exploration, various immobilization methods for different biofunctional materials have been established. Physical adsorption This method involves the adsorption of biocomponents onto insoluble and inert carriers through the action of polar, hydrogen and hydrophobic bonds of biomolecules. Several materials have been reported in the literature as carriers for the adsorption of other materials, such as graphite powder [25], graphite-polytetrafluoroethylene [26], activated carbon [27], and ion-exchange resins [28].