Comparison of two glutathione S-transferases used in capacitive biosensors for detection of heavy metals

ISSN： 0306-7319

Source： International Journal of Environmental and Analytical Chemistry, Vol.87, Iss.10-11, 2007-08, pp. : 745-754

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

This work describes the development of a heavy-metal biosensor based on either recombinant 6His-Tag glutathione S-transferase (GST-(His)6) or glutathione S-transferase Theta 2-2 (GST-theta 2-2), and a capacitive transducer. The dynamic range of the pure bovine liver GST-Theta 2-2 biosensor was 1 fM to 1 mM for Zn2+, and 10 pM to 1 mM for Cd2+. The GST-(His)6 biosensor was able to detect Zn2+ and Cd2+ in the range of 1 fM to 10 µM, and Hg2+ in the range of 1 fM to 10 mM. The bovine liver GST Theta 2-2 biosensor displays an increased selectivity and a wider dynamic range for Zn2+ compared with the GST-(His)6 biosensor. Therefore, by using different GST isozymes, it is possible to modulate important characteristics of capacitive biosensors for the detection of heavy metals.