Amperometric biosensor for catechol using electrochemical template process

Abstract

A novel amperometric biosensor for the determination of catechol was developed accordingly to the electrochemical template procedure. The optimum fabricating conditions of the biosensor were studied. The resulting biosensor with the limit of less than 0.05μM can be used for detection of catechol in the linear range of 2.5–140μM. The maximum response current (Imax) and the Michaelis–Menten constant (k′m) are 3.08μA and 77.52μM, respectively. The activation energy (Ea) of the polyphenol oxidase (PPO) catalytic reaction is 25.56kJmol−1 in the B–R buffer. The stability of the PANI-CA biosensor fabricated with the electrochemical template process (retains 86% of the original activity after four months) is much higher than that fabricated with one-step and two-step processes (retains 75% of the original activity after four months). The effects of potential and pH on the response current of the biosensor are also described.