Electrochemical Impedance Analysis of Biofunctionalized Conducting Polymer-Modified Graphene-CNTs Nanocomposite for Protein Detection

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• 作者：Shobhita Singal ; Avanish K. Srivastava ; Rajesh
• 关键词：Conducting polymer ; Graphene ; Carbon nanotube ; Hybrid ; Transducer ; Protein antigen cTnI ; Electrochemical impedance
• 刊名：Nano-Micro Letters
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：9
• 期：1
• 全文大小：1,367 KB
• 刊物类别：Nanotechnology and Microengineering; Nanotechnology; Nanoscale Science and Technology;
• 刊物主题：Nanotechnology and Microengineering; Nanotechnology; Nanoscale Science and Technology;
• 出版者：Springer Berlin Heidelberg
• ISSN：2150-5551
• 卷排序：9

文摘

We report an electrodeposited poly(pyrrole-co-pyrrolepropylic acid) copolymer modified electroactive graphene-carbon nanotubes composite deposited on a glassy carbon electrode to detect the protein antigen (cTnI). The copolymer provides pendant carboxyl groups for the site-specific covalent immobilization of protein antibody, anti-troponin I. The hybrid nanocomposite was used as a transducer for biointerfacial impedance sensing for cTnI detection. The results show that the hybrid exhibits a pseudo capacitive behaviour with a maximum phase angle of 49° near 1 Hz, which is due to the inhomogeneous and porous structure of the hybrid composition. The constant phase element of copolymer is 0.61 (n = 0.61), whereas, it is 0.88 (n = 0.88) for the hybrid composites, indicating a comparatively homogeneous microstructure after biomolecular functionalization. The transducer shows a linear change in charge transfer characteristic (R_et) on cTnI immunoreaction for spiked human serum in the concentration range of 1.0 pg mL−1–10.0 ng mL−1. The sensitivity of the transducer is 167.8 ± 14.2 Ω cm2 per decade, and it also exhibits high specificity and good reproducibility.