Patent ID: 8702924

Claim:
An electrode for determining the H 2 O 2 concentration in a liquid sample, the electrode comprising: a conductor; and an active layer formed on said conductor and including a polybenzimidazole polymer that contains at least one of the functional group of the following formula: wherein said polybenzimidazole polymer contains a repeating unit represented by the following formula: in which X 1 is a tetravalent aromatic group including two phenyl groups, each of said phenyl groups is bonded with the nitrogen atoms in said formula to form two benzimidazole rings; each of R 4 and R 5 , independently, is hydrogen, a C 1 to C 12 alkyl group, or —(C═O)—Z—COOM, Z being ethylene or vinylene, and M being hydrogen; Y 1 is a single bond, a C 2 to C 20 divalent aromatic group, a C 2 to C 20 divalent aliphatic group, or a C 2 to C 20 divalent alicyclic group; and n1 is an integer ranging from 10 to 1000.