表面電気化学的手法による高感度化学センシング技術の開発に関する研究

概要

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A novel and highly sensitive electrochemical method has been developed for the determination of thiol compounds, based on the chemisorption/electrochemical desorption-procedure of the analyte on a metal electrode. The chemisorption (i.e. accumulation) of the analyte resulted in an enhanced sensitivity for an electrochemical measurement of the thiol compared to a direct determination of the same analyte without any accumulaion. Our thiol-sensing method was successfully applied to a highly sensitive measurement of an enzyme, acetylcholinesterase (AChE). Thiocholine, which was produced through the AChE-catalyzed reaction, was chemisorbed on a silver electrode, and was then electrochemically desorbed. The electrical charge that passed through the desorption process was proportional to the number of adsorbed thiocholine molecules, and hence to the AChE activity. The detection limit was 0.01 U l^<-1>, which was one-hundred times lower than that obtained with a conventional amperometric method. Organophosphorus pesticides, diazinon (0.01〜0.05mg l^<-1>) and ethylthiometon (0.01〜0.2mg l^<-1>) could be measured by monitoring the activity change of AChE, based on the method mentioned above. We developed an enzyme immunoassay system for the determination of B-type natriuretric peptide (BNP). The detection limit was as low as 40ng l^<-1>. An automated system at an inexpensive BNP assay could soon be realized.
社団法人日本分析化学会の論文
2006-02-05