| abstract |
Disclosed is a high performance biosensor free from the effect of any components existing in a sample solution other than a substrate. The biosensor comprises an electrically insulating base plate, an electrode system including a working electrode and a counter electrode provided on the base plate, and a reaction layer containing a hydrophilic polymer, an enzyme and an electron acceptor located over the electrode system. The reaction layer contains an excess amount of hydrophilic polymer in a range of 150 to 1,000% by weight of the enzyme. |