COMPARISON OF TWO PHOTOSYNTHETIC BIOMEDIATORS FOR HERBICIDE DETECTION.

Monitoring programs require rapid, simple and low-cost screening procedures for the detection of harmful chemicals in the environment. Photosynthetic biosensors better reflect the impact of toxic compounds by measuring the alteration of a physiological process [14,17]. Under illumination, photosynthetic materials are able to transfer electrons to an electron acceptor changing its redox state; the electric current generated can be measured amperometrically. The present work focuses on the construction and comparison of two photosynthesis-based biosensors using either thylakoid membrane or photosynthetic algae. This setup resulted in two reusable amperometric biosensors for the detection of herbicides both with limits of detection in the nanomolar range. The algal biosensor, as it was expected, presented an increased lifetime. [ABSTRACT FROM AUTHOR]