Whole cell based amperometric sensor with relative selectivity for zinc ions

摘要

A whole cell based amperometric biosensor was fabricated using unicellular microalgae Chlorella sp. as the biocatalyst, entrapped in a polymeric membrane directly interfaced to the surface of a platinum electrode for the detection of bioavailable heavy metal ions like zinc, copper, cadmium, cobalt and nickel with a life time of 7 days. The proposed system is sensitive to a lower concentration range of 10?9 M of nickel ions, 10?10 M of cadmium and cobalt ions, 10?11 M of copper and zinc ions. The amperometric biosensor responds to heavy metal ions with a relative selectivity in the order: Zn2+ Cu2+ Cd2+ Co2+ Ni2+. The proposed analytical method has been validated with atomic absorption spectroscopy for heavy metal detection in real time samples...