TY - JFULL AU - Yusmeeraz Yusof and Yoshiyuki Yanagimoto and Shigeyasu Uno and Kazuo Nakazato PY - 2011/2/ TI - Electrical Characteristics of Biomodified Electrodes using Nonfaradaic Electrochemical Impedance Spectroscopy T2 - International Journal of Chemical and Molecular Engineering SP - 28 EP - 33 VL - 5 SN - 1307-6892 UR - https://publications.waset.org/pdf/9402 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 49, 2011 N2 - We demonstrate a nonfaradaic electrochemical impedance spectroscopy measurement of biochemically modified gold plated electrodes using a two-electrode system. The absence of any redox indicator in the impedance measurements provide more precise and accurate characterization of the measured bioanalyte at molecular resolution. An equivalent electrical circuit of the electrodeelectrolyte interface was deduced from the observed impedance data of saline solution at low and high concentrations. The detection of biomolecular interactions was fundamentally correlated to electrical double-layer variation at modified interface. The investigations were done using 20mer deoxyribonucleic acid (DNA) strands without any label. Surface modification was performed by creating mixed monolayer of the thiol-modified single-stranded DNA and a spacer thiol (mercaptohexanol) by a two-step self-assembly method. The results clearly distinguish between the noncomplementary and complementary hybridization of DNA, at low frequency region below several hundreds Hertz. ER -