<strong>Evaluation of sensor performance for harmful compounds by using photo-induced electron transfer from photosynthetic membranes to electrodes</strong>

Abstract

Abstract:The effect of harmful compounds such as KCN, phenol, and herbicides on the photocurrent of photosynthetic membranes (so-called chromatophores) was investigated using carbon paste electrodes. The photocurrent-time curve of photo-induced electron transfer from chromatophores of the purple photosynthetic bacterium Rhodobacter sphaeroides to the electrode via 2,5-dichloro-1,4-benzoquinone (DCBQ) was composed of two characteristic phases: an abrupt increase in current immediately after illumination (I0), and constant current over time (Ic). Photo-reduction of DCBQ exhibited Michaelis- OPEN ACCESS 2Menten-like kinetics, and reduction rates were dependent on the amount of DCBQ and the photon flux intensity. The Ic decreased in the presence of KCN at concentrations over 0.05). The I0 decreased selectively following addition of phenol at concentrations over 20 μM. The Ic was affected by terbutryn only at concentrations over 10 μM. In contrast, DCMU and atrazine had no effect on either I0 or Ic. The utility of this electrode system for the detection of harmful compounds is also discussed.