Novel synthetic phytochelatin-based capacitive biosensor for heavy metal ion detection

A novel capacitance biosensor based on synthetic phytochelatins for sensitive detection of heavy metals is described. Synthetic phytochelatin (Glu-Cys)(20)Gly (EC20) fused to the maltose binding domain protein was expressed in Escherichia coli and purified for construction of the biosensor. The new biosensor was able to detect Hg2+, Cd2+, Ph2+, Cu2+ and Zn2+ ions in concentration range of 100 fM- 10 mM, and the order of sensitivity was S-Zn > S-Cu > S-Hg much greater than S-Cd congruent to S-Pb. The biological sensing element of the sensor could be regenerated using EDTA and the storage stability of the biosensor was 15 days. (C) 2003 Elsevier Science B.V. All rights reserved.