Optical algal biosensor using alkaline phosphatase for determination of heavy metals.

A biosensor is constructed to detect heavy metals from inhibition of alkaline phosphatase (AP) present on the external membrane of Chlorella vulgaris microalgae. The microalgal cells are immobilized on removable membranes placed in front of the tip of an optical fiber bundle inside a homemade microcell. C. vulgaris was cultivated in the laboratory and its alkaline phosphatase activity is strongly inhibited in the presence of heavy metals. This property has been used for the determination of those toxic compounds. (c) 2002 Elsevier Science (USA).