Pyrrole electropolymerization conditions for fabrication of microelectrode array within phenol biosensor

Abstract

This research is the study of horseradish peroxidase (HRP) and polypyrrole (PPY) co-immobilization onto sonochemical fabricated microelectrode arrays for phenol detection. This microelectrode was fabricated based on glassy carbon electrode. An enzyme and pyrrole were electropolymerized onto 25min sonicated microelectrode arrays of ablated polydiaminobenzene film. Optimal fabrication conditions of microelectrode arrays for phenol detection were studied, namely, number of cycles and scan rate for pyrrole electropolymerization, pyrrole and HRP concentrations, respectively. Suitable microelectrode biosensors in this research were fabricated from co- electropolymerization of 250 U/ml HRP and 0.05M pyrrole at 20mV/s scan rate for 20cycles. Linear range of this biosensor was found in from 2-100 μM. The sensitivity of this biosensor was 0.1053 nA/ μM and the detection limit of 4.55 μM phenol was obtained. The response time of this biosensor was found within 150 s. However, the current response of this biosensor decreased to 50% of the initial current after 10 repeated tests, and lost 54% of its initial response on the second day of storage. Moreover, the R.S.D. of this microelectrode reproducibility was 23.84%.