American Chemical Society, ACS Applied Materials and Interfaces, 20(6), p. 17887-17893, 2014
DOI: 10.1021/am5046026
Full text: Download
We report on the fabrication of complex electrode architectures for efficient direct bioelectrocatalysis. In the developed procedure, the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH) entrapped in a sulfo-natedpolyaniline [poly(2-methoxyaniline-5-sulfonic acid)-co-aniline; PMSA1] was immobilized on macroporous indium tin oxide (macroITO) electrodes. The use of the 3D-conducting scaffold with a large surface area in combination with the redox polymer enables immobilization of large amounts of enzyme and its efficient communication with the electrode, leading to enhanced direct bioelectrocatalysis. In the presence of glucose the fabricated bioelectrodes show an exceptionally high direct bioelectrocatalytical response without any additional mediator. The catalytic current is increased more than 200-fold compared to plane ITO electrodes. Together with a high long-term stability (the current response is maintained for >90% of the initial value even after two weeks of storage), the transparent 3D macroITO structure with a conductive polymer represents a valuable basis for the construction of highly efficient bioelectronic units, which are useful as indicators for processes liberating glucose and allowing optical and electrochemical transduction.