Photosystem II-modified gold electrodes providing direct mediatorless electron transport based on an electrodeposited layer of conductive poly (mercapto-p-benzoquinone). such electrodes are suitable for manufacturing biosensors for herbicides or microphotovoltaic cells. Sulfobenzoquinone was prepared by organic synthesis. A poly (mercapto-p-benzoquinone) layer was synthesized on screen-printed gold electrodes and microelectrodes in a silicon microarray via an electrochemical oxidation process of sulfo-p-benzoquinone at+ 650 mV vs. Ag/AgCl. The basic properties of the poly (mercapto-p-benzoquinone) layer were characterized by linear sweep voltammetry and atomic force microscopy. Redox behaviour typical for quinones was observed. Photosystem II particles isolated from thermophilic cyanobacteria (Synechococcus bigranulatus) were immobilized on gold electrodes covered by poly (mercapto-p-benzoquinone). Photocurrent generation was observed at E=+ 250 mV (vs. Ag/AgCl) without the addition of any mediator. The optimal length of the polymer that provides direct mediatorless electron transport was found to be very close to 30 nm.
1 Jan 2005
Volume: 51 Issue: 1 Pages: 48-60
Energia, ambiente e innovazione