The intrinsic redox reactions of polyamic acid derivatives and their application in hydrogen peroxide sensor.

Polyamic acids (PAAs) containing benzothiazole (BT) and benzoxazole (BO) pendent groups (PAA-BT and PAA-BO, respectively) which possessed electroactivity were synthesized successfully. The addition of H(2)O(2) chemically oxidized the intrinsic carboxylic acid groups of PAA to form peroxy acid groups, and the peroxy acid further oxidized the electroactive sites of BT and BO to form N-oxides. The N-oxides could be reverted to their original form by electrochemical reduction, thus increasing the electrochemical reductive current.