Plant power: electrochemical energy conversion using photosystem I

AGRO 112

David E. Cliffel, d.cliffel@vanderbilt.edu1, Mădălina Ciobanu, madalina.ciobanu@vanderbilt.edu1, G Kane Jennings, jenningk@vuse.vanderbilt.edu2, Yan Xun1, and Morgan Krim1. (1) Department of Chemistry, Vanderbilt University, VU Station B 351822, Nashville, TN 37235-1822, (2) Chemical Engineering, Vanderbilt University, Box 1604 Station B, Nashville, TN 37235
Photosystem I (PSI) as one of nature's photodiodes is a perfect candidate for agro-nanotechnology studies leading towards biologically-inspired molecular electronics. In order to integrate it into devices, we have selectively orientated its electron transfer vector on patterned substrates. Scanning Electrochemical Microscopy (SECM) imaged the directed adsorption of PSI at patterned surfaces containing discreet regions of CH3- and HO-terminated SAMs. SECM is an in situ scanning probe microscopy that rasters an ultramicroelectrode tip across the surface, measuring the electrochemical gradients generated at a surface. The electrochemical surface image provides information about the uniformity of adsorption as well as the biolayer thickness. Direct protein voltammetry on photosystem I has identified the electron donor, P700, and the electron acceptor sites, FAB, and the observed potential values (EP700 = 0.5 V vs. NHE (Normal Hydrogen Electrode); EFAB = -0.5 V vs. NHE) correlate with the literature. Photoelectrochemical experiments demonstrate the ability of these PSI electrodes to convert light into photocurrents.
 

Nanotechnology in Agriculture
8:30 AM-11:40 AM, Wednesday, August 22, 2007 BCEC -- 259A, Oral

Division of Agrochemicals

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007