Development of protein imprints on carbon nanotube for biosensing
L. Ren, H.-Z. Zhao, A. Cimeno, C.-J. Xu, Y. Yu, T. Chiles, M. Naughton, D. Cai
Boston College, US
Keywords: molecular imprint, sensor, electropolymerization, carbon nanotube
Abstract:We are using electropolymerization method to establish a polyphenol nanocoating on carbon nanotube (CNT) array. Polyphenol is a non-conductive polymer. Its electropolymerization on carbon nanotubes entitles a self-limiting process that can repetitively coat CNT at nanoscale (~15 nm) thickness. Ferritin is an iron storage protein especially in mammalian bloods. Its abnormal level, either high or low, will lead to hemochromatosis or amenia. The ferritin imprinted cavities can be developed after buffer rinsing of polyphenol film with ferritin entrapment. The imprints hold an intrinsic affinity to the template proteins that enables the specific biorecognition. Electrochemical impedance spectroscopy and other electrochemistry techniques were used to evaluate the polyphenol coating, development of molecular imprints and conduct protein detections. Due to the extreme thickness of the imprinted polymer coating, significant impedance changes were observed at the stage of initial coating, formation of the imprints, rebinding of ferritin and elution of the captured ferritin. Therefore, the sensor exhibited fast response, high sensitivity and selectivity for the demonstration of ferritin detection. The herein introduced development strategy is applicable to the fabrication of high performance protein sensors for clinic diagnosis, food and drink quality control and biowarfare detections.