PHOTOELECTROCHEMICAL CELL CONTAINING CHLOROPLAST MEMBRANES AS A BIOSENSOR FOR PHYTOTOXICITY MEASUREMENTS

A photoelectrochemical cell using thylakoid membranes isolated from spinach leaves was used to elaborate a phytotoxicity biosensor. It is shown that the photocurrent generated in the cell is linearly correlated with the electron transport activity of the photosynthetic membranes. In the presence of toxic compounds that inhibit electron transport, the photocurrent was reduced in proportion to their inhibitory effect. Immobilized thylakoid membranes, with their longer lifetime of biological function, could also be used. It was deduced that herbicides, heavy metals and other chemicals which affect the growth of the phytoplankton owing to their action at the level of photosynthetic electron transport, could be quickly detected using this electrochemical cell as a phytotoxicity biosensor.