Cyclic voltammetry and voltabsorptometry studies of redox proteins immobilised on nanocrystalline tin dioxide electrodes

Protein film cyclic voltammetry is a well-established technique for the study of redox proteins immobilised on electrode surfaces. In this paper, we use nanostructured SnO2 electrodes to demonstrate that cyclic voltabsorptometry is an effective, complimentary approach to such studies of protein redox function. We exemplify this approach using two different redox systems: microperoxidase-11 (MP-11) and flavodoxin Desulfovibrio vulgaris Hildenborough (Fld). Both systems were immobilised on nanocrystalline SnO2 electrodes and the resulting films investigated by simultaneous cyclic voltammetry and voltabsorptometry. We demonstrate that cyclic voltabsorptometry allows the unambiguous and background free observation of redox reactions for both systems studied.