A Microbial Sensor Based on Direct Electron Transfer at Shewanella Sp Drop-Coated Screen-Printed Carbon Electrodes

Aerobically grown Shewanella sp. bacterial suspension drop-coated on a disposable screen-printed carbon electrode was found to possess electroactivity without the aid of redox mediator. Cyclic voltammetric studies revealed the characteristics of a mixed diffusion adsorption-controlled electrochemical process for direct electron transfer at the bacteria-modified electrode. Both FE-SEM and ATR FT-IR experiments were carried out to investigate the surface characteristics. The electroanalytical applicability was further demonstrated for electrocatalytic reduction of arsenite, hydrogen peroxide and nitrite. Low cost and very simple manufacturing procedure allow for the proposed bacterial sensor to be applied as disposable devices.