Polymer film for biosensor and preparation method therefor

A polymer film used for a biosensor, which is a diffusion-limiting film for controlling diffusion of a glucosidase enzyme, wherein:

• the polymer film has a three-dimensional network structure formed by a natural high-molecular polymer and a synthetic high-molecular polymer via a plurality of crosslinking modes;
• the three-dimensional network structure comprises a chemically crosslinked network and a reversible physically crosslinked network, the chemically crosslinked network being formed by covalent bond crosslinking and the reversible physically crosslinked network being formed by ionic bond crosslinking;
• the chemically crosslinked network has covalent bond crosslinking between the synthetic high-molecular polymers and covalent bond crosslinking between the natural high-molecular polymer and the synthetic high-molecular polymer;
• the physically crosslinked network has ionic bond crosslinking between the natural high-molecular polymers;
• both the natural high-molecular polymer and the synthetic high-molecular polymer are hydrophilic polymers;
• and
• the natural high-molecular polymer is hydroxymethyl chitosan, and the synthetic high molecular polymer is poly-4-vinylpyridine.