Abstract
Highly crystalline polydopamine decorated cobalt oxide (Co3O4) sheets, designated as CoPDA are synthesized from amorphous alpha-Co(OH)(2) microspheres (CoMSPs) through acid restructuring process without pyrolysis or photo-irradiation. Structure and morphology of this product are analyzed by using spectroscopic and microscopic techniques. As-prepared CoPDA along with added reduced graphene oxide (r-GO) is explored for the electrochemical detection of L-histidine (L-His) under optimized condition. The electrochemical response of CoPDA/r-GO composite coated onto glassy carbon electrode toward the oxidation of L-His shows a linear response over a wide concentration range with a sensitivity of 4.47 mu A/mM. The limit of detection value is calculated to be 1.5 mu M with a response time of 17 seconds. The proposed sensor matrix is found to be highly selective for L-His among other interfering amino acids. Real sample analysis is carried out for the estimation of L-His using commercial L-His supplements. These studies suggest the promising use of this proposed electrochemical sensor for efficient detection of L-His possessing better selectivity and sensitivity. (C) 2018 The Electrochemical Society.