Development of a Mediator-Type Bioelectrochemical Sensor Based on Polypyrrole Immobilized Ferricyanide and Microorganisms for Biochemical Oxygen Demand Fast Detection

摘要

A mediator-type bioelectrochemical sensor was developed by using polypyrrole (PPy) immobilizedferricyanide (FC) as mediator and immobilized Pseudomonas aeruginosa (P. aeruginosa) as abiosensing film for biochemical oxygen demand (BOD) fast detection. The sensor chip consists of athree-electrode system, with Au working electrode (WE), Pt counter electrode (CE) and Pt pseudo- reference electrode (RE) compactly integrated as a disposable using micro-electro-mechanism system(MEMS) technology. The FC mediator and P. Aeruginosa microorganisms have been embedded inPPy matrix on gold microelectrode surface during the electropolymerization of pyrrole monomer usingelectrochemical cyclic voltammetry (CV) method. This bioelectrochemical sensor responds to BODdue to yielded ferrocyanide during catalytic reduction by metabolic reactions of microorganisms. Agood linear correlation with chemically determined BOD values was obtained from 5 to 100 mg/L withfast response time. The proposed sensor in this paper is significant for BOD fast detection.