Construction of photobiocathodes using multi-walled carbon nanotubes and photosystem I

In this work, we report on the successful assembly of cyanobacterial photosystem I (PSI) on carbon nanotubes for light-to-current conversion applications. For this purpose, glassy carbon electrodes (GCE) have been modified with multi-walled carbon nanotubes (MWCNTs). The surface of the MWCNTs has been adjusted in a non-invasive way by the use of a carboxylated pyrene derivative to achieve a covalent fixation of PSI. Our results show a cathodic photocurrent response and functionality of the biohybrid electrode upon illumination. The experiments verify that the photocurrent generation can clearly be attributed to a functional PSI on the electrode interface. An additional implementation of cytochrome c (cyt c) into this electrode architecture results in a 25-fold enhancement of cathodic photocurrent response (0.8 to 18Acm(-2) at -100mV and 100mWcm(-2)), which can be attributed to an improved connection of PSI with the underlying electrode. [GRAPHICS] . (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim