Study on Electrochemical Insulin Sensing Utilizing a DNA Aptamer-Immobilized Gold Electrode

Materials

Izumi Kubo¹  Taiga Eguchi² 

[1] Graduate School of Engineering, Soka University, 1-236 Tangi, Hachioji, Tokyo, 192-8577, Japan; E-Mail

关键词: DNA aptamer;    hemin;    insulin;    glucagon;    G-quadruplex;    peroxidase activity;    gold electrode;   

DOI  :  10.3390/ma8084710

来源: mdpi

【 摘 要 】

We investigated an insulin-sensing method by utilizing an insulin-binding aptamer IGA3, which forms an anti-parallel G-quadruplex with folded single strands. Spectroscopic observation indicates that some anti-parallel G-quadruplex bind hemin and show peroxidase activity. In this study, the peroxidase activity of IGA3 with hemin was confirmed by spectrophotometric measurements, i.e., the activity was three-times higher than hemin itself. IGA3 was then immobilized onto a gold electrode to determine its electrochemical activity. The peroxidase activity of the immobilized IGA3-hemin complex was determined by cyclic voltammetry, and a cathodic peak current of the electrode showed a dependence on the concentration of H₂O₂. The cathodic peak current of the IGA3-hemin complex decreased by binding it to insulin, and this decrease depended on the concentration of insulin.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.