title: A novel electrochemical method to determine α-amylase activity.
abstract: In this paper, we report a novel electrochemical method that can be developed as a biosensor for simple and direct determination of α-amylase activity. The method is based on the hydrolysis of maltopentaose, the substrate of the enzyme, which is immobilized on the surface of a gold electrode, and the induced charge changes of the substrate-modified electrode. Specifically, the substrate maltopentaose is immobilized onto a gold electrode surface via a simple and direct immobilization technique that involves a one-step and site-specific attachment of unmodified maltopentaose to the hydrazide-derivatized surface. So, by analyzing the electrochemical signal obtained from the electro-active molecule [Ru(NH3)5Cl](2+) during the hydrolysis of maltopentaose, the determination of α-amylase activity is achieved. Under optimized conditions, α-amylase activity can be assayed with a detection limit of 0.022 U mL(-1). The biosensor exhibits a rapid response, good stability and anti-interference ability. Furthermore, the biosensor has also been successfully applied to detect α-amylase in human serum, which shows acceptable accuracy compared to the currently used clinical method. The proposed method in this work may also have potential application of α-amylase determination in real blood samples, diagnostics and food production in the future.
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, P. R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.forename: Junhui
authors.initials: J
authors.lastname: Cui
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Chen
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D057075:Enzyme Assays / Q000379:methods; D006801:Humans; D057230:Limit of Detection; D009844:Oligosaccharides / Q000378:metabolism; D000516:alpha-Amylases / Q000032:analysis / Q000097:blood* / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; C019193:maltopentaose; D000516:alpha-Amylases