Title: Conductometric enzyme biosensor for determination of heavy metal ions in water solution

Biography:

Viktoriya Pyeshkova defended her PhD thesis in Institute of Molecular Biology and Genetics of NAS of Ukraine (IMBIG) in 2010 in Kiev. Now she is Senior Researcher at IMBIG. Viktoriya is co-author of 32 scientific articles, 3 patents and over 40 communications (oral/poster) in international conferences. She has more than 10 years’ experience in development of biosensors for medical, ecological and food control purposes. In cooperation with colleagues she successfully developed new effective electrochemical biosensors for determination of carbohydrates, ammonium, urea, arginine and toxic compounds.

Abstract

The detection of toxic compounds is an important issue for environmental remediation and is an integral part of the risk assessment of environmental pollution. This work is devoted to the development and optimization of the enzyme conductometric biosensor for the inhibitory analysis of heavy metal ions in water solution. A pair of planar thin-film interdigitated electrodes (gold and platinum), deposited on a ceramic and glass substrate, were used as a conductometric transducers. The three enzymes (invertase, mutarotase,  glucose oxidase) immobilized on the transducer surface were used as a sensitive biological element. The optimal enzyme amount and enzymes ratio in the bioselective membrane were found considering the enzyme activity, biosensor sensitivity to substrate (sucrose and glucose) and heavy metal ions. EDTA and cysteine solutions were used for biosensor reactivation. The measurement conditions were optimized. The optimal time for incubation of biosensor in solution of toxic compounds was 10-30 minutes. The optimal concentration of sucrose for inhibitory analysis was 1.25 mM. The main analytical characteristics of the biosensor (sensitivity to different heavy metal ions, signal reproducibility, selectivity) were studied. The biosensor demonstrated the highest sensitivity toward Ag⁺ and Hg⁺². The biosensor was tested in the work with samples of water contaminated with heavy metal ions. The obtained results showed high correlation with results obtained by standard traditional method of heavy metal ions determination. This biosensor can be used for monitoring of water toxicity.