The activity of immobilized laccase, from Trametes versicolor,on an electroploymerized poly(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methanol (PEDOT-OH) modified microelectrode for use as a bio-cathode in an enzymatic biofuel cell was measured electrochemically.  The activity of laccase, prior to immobilization, was determined by measuring the absorbance of an enzymatically oxidized substrate, syringaldazine, by using UV-Vis spectrophotometry.  The bio-cathode was constructed by modifying a gold microband electrode with PEDOT-OH and then immobilized laccase by cross-linking with glutaraldehyde, stabilizing with bovine serum albumin, and drop casting onto the electrode surface.  Cyclic voltammetry was used to characterize the electrode behavior both prior to and after modification with PEDOT-OH and laccase.  Chronoamperometry was conducted to measure the current response of the modified microelectrode as a function of increasing analyte concentration.  The data showed an increase in current density upon polymerization of the conductive polymer and an increase in current density with the immobilized laccase only when a mediator was present in the system.   

References

1.         Heller, A., Miniature biofuel cells. Physical Chemistry Chemical Physics, 2004. 6(2): p. 209.

2.         Meredith, M.T. and S.D. Minteer, Biofuel cells: enhanced enzymatic bioelectrocatalysis. Annu Rev Anal Chem (Palo Alto Calif), 2012. 5: p. 157-79.

3.         Gupta, G., V. Rajendran, and P. Atanassov, Laccase Biosensor on Monolayer-Modified Gold Electrode. Electroanalysis, 2003. 15(20): p. 1577-1583.

4.         Ribeiro, F.W.P., et al., Simple laccase-based biosensor for formetanate hydrochloride quantification in fruits. Bioelectrochemistry, 2014. 95: p. 7-14.

5.         Guerrieri, A., et al., Electrosynthesized non-conducting polymers as permselective membranes in amperometric enzyme electrodes: a glucose biosensor based on a co-crosslinked glucose oxidase/overoxidized polypyrrole bilayer. Biosensors and Bioelectronics, 1998. 13(1): p. 103-112.

6.         Zebda, A., et al., Mediatorless high-power glucose biofuel cells based on compressed carbon nanotube-enzyme electrodes. Nat Commun, 2011. 2: p. 370.