Characterization of a First-Generation Microbial Fuel Cell and its Possible Applications in Environmental Chemistry

SANTIAGO A. CHIAPPINI; PISANI, P. H. D.; EDUARDO CORTON

Proceedings del 5º Congreso Iberoamericano de Sensores, Ibersensor 2006

Ibersensors

Lugar: DF; Año: 2006 p. 1 - 6

1697-2473

Environmental biosensors are a growing area of application, despite the still small participation on the worldwide biosensor market, where clinical glucose sensors explain close to 90% of the total sales. Several bioanalytical parameters, as BOD (biochemical oxygen demand and toxicity, among others) are related or can be related to the measurement of metabolic respiratory activity or related parameters. The utilization of a microbial mediated fuel cell (also called first generation fuel cell) as microbial metabolism detector was studied, and several critical parameters (as mediator concentration, microbial load, incubation time) described.             Our microbial fuel cells are based on carbon electrodes and Nafion® as proton transporter membrane. Different microbial strains, S. cerevisiae, E. coli and Lactobacillus sp. were assayed in their capacity to reduce two redox mediators; these soluble redox mediators (methylene blue and neutral red) are capable to take electrons from cellular oxidative metabolism and transfer it to the surface of an electrode.    dcvbdfgtryu65 zxse2            Using anaerobic/facultative strains as E. coli we obtain open circuit voltages up to 500 mV, current and charge were correlated with the concentration of microbial cells in the biotic compartment and also with the glucose or others carbon sources in the biotic compartment. Measured current was in the microampere range when the cell was discharged using a 10 kΩ resistor. The utilization of this transducer as BOD sensor was studied with the more commonly used BOD standards, a glucose-glutamic acid solution (GGA) and OECD solution (a rather more complex solution). The biosensor was used in batch experiments or as detector in a FIA system, in a typical set-up, by using a peristaltic pump and a low pressure 6 ways injector valve.