Amperometric phenol biosensor based on laponite clay-chitosan nanocomposite matrix.

A novel strategy to fabricate an amperometric biosensor for phenol determination based on chitosan/laponite nanocomposite matrix was described. The composite film was used to immobilize PPO on the surface of a glassy carbon electrode. Chitosan was utilized to improve the analytical performance of the pure clay-modified bioelectrode. The biosensor exhibited a series of properties: good affinity to its substrate (the apparent Michaelis-Menten constant for the sensor was found to be 0.16 mM), high sensitivity (674 mA M(-1)cm(-2) for catechol) and remarkable long-term stability in storage (it retains 88% of the original activity after 60 days). In addition, optimization of the biosensor construction as well as effects of experimental variables such as pH, operating potential and temperature on the amperometric response of the sensor were discussed.