Impedance Biosensor Incorporating a Carboxylate-Terminated Bidentate Thiol for Antibody Immobilization. Issue 5 (1st January 2016)

• Record Type: Journal Article
• Authors: Radhakrishnan, Rajeswaran; Pali, Madhavi; Lee, Han Ju; Lee, T. Randall; Suni, Ian I.
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 5(2016)
• Page Start: B125
• Page End: B130
• Publication Date: 2016-01-01
• Subjects: Biosensor -- Electrochemical Impedance Spectroscopy -- Regeneration; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0301605jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : An impedance biosensor is reported that employs the bidentate thiol, 16-[3, 5-bis(mercaptomethyl)phenoxy]-hexadecanoic acid (BMPHA), as a bifunctional reagent for antibody immobilization atop an Au electrode, and the results are compared to those obtained for the analogous monodentate reagent, 16-mercaptohexadecanoic acid (16 MHA). The detection limit for peanut protein Ara h 1 on the BMPHA bidentate thiol- coated Au electrode is approximately 0.71 ng/mL (0.01 nM), about 3x lower than that obtained on the comparable monodentate (16-MHA) thiol-coated Au electrode. Daily impedance measurements were employed to study antibody regeneration with a mild denaturing agent, 0.2 M KSCN at pH 7.3. The antibody-coated electrodes retained activity toward Ara h1 for 10 and 20 days of regeneration of the monodentate- and BMPHA-coated Au electrodes, respectively, illustrating the superior stability of protein films atop the BMPHA bidentate thiol.