Spectroelectrochemical examination of the interaction between bacterial cells and gold electrodes

JUAN PABLO BUSALMEN; BERNÁ GALIANO, ANTONIO; MIGUEL FELIU, JUAN

Toulouse

Congreso; XIXth International symposium on Bioelectrochemistry and Bioenergetics; 2007

Bioelectrochemical Society

The interaction between bacterial cell of Pseudomonas fluorescens (ATCC 17552) and well defined gold surfaces was analyzed by cyclic voltammetry and ATR-SEIRAS. The double layer capacitance of single-crystal gold electrodes was found to decrease with the adhesion of cells. The adsorption of bacterial cells, mainly indicated by the increase in the amide I and amide II protein related bands, was found to interfere with the ice-like structure of water in association to surface. Also, the displacement of interfacial bound water was observed to be proportional to bacterial adsorption.    During polarization at an oxidation potential (i.e. 0.7 V), bacterial cells were found to get closer to the gold surface. It was indicated by the increment in the main IR bacterial signals. A sudden increment in the signal at 1235 cm−1 is proposed to be due to the oxidation of the lipopolysaccharides on the outermost bacterial surface. The causal relation of results presented here with previously reported polarization effects on attached cells growth is discussed.