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

Saatci E., Nistor M., Gaspar S., Csoregi E., Iscan M.

INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY, vol.87, pp.745-754, 2007 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 87
  • Publication Date: 2007
  • Doi Number: 10.1080/03067310701409309
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.745-754
  • Keywords: capacitive biosensor, 6His-tag glutathione S-transferase, bovine liver glutathione S-tranferase theta 2-2, heavy-metal detection


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 1mM for Zn2+, and 10pM to 1mM for Cd2+. The GST-(His) 6 biosensor was able to detect Zn2+ and Cd2+ in the range of 1 fM to 10 mu M, and Hg2+ in the range of 1 fM to 10mM. 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.