Facile Fabrication of a Selective Poly(caffeic acid)@MWCNT-Ni(OH)2 Hybrid Nanomaterial and Its Application as a Non-Enzymatic Glucose Sensor

Abstract

A novel catechol-based PCA@MWCNT-Ni(OH)2 hybrid material was prepared and used to construct a non-enzymatic glucose biosensor. In this synthesis, MWCNTs were covered with a poly(caffeic acid) coating and then subjected to a straightforward electrochemical process to decorate the hybrid material with Ni(OH)2 particles. The physicochemical properties and morphology of the nanomaterial were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). Amperometry and cyclic voltammetric studies demonstrated the enhanced redox properties of a GC/PCA@MWCNT-Ni(OH)2 electrode and its electrocatalytic activity in glucose detection, with a low detection limit (0.29 μM), a selectivity of 232.7 μA mM−1 cm−2, and a linear range of 0.05–10 mM, with good stability (5 months) and reproducibility (n = 8). The non-enzymatic sensor was also used for glucose determination in human serum and human blood, with recovery values ranging from 93.3% to 98.2%. In view of the properties demonstrated, the described GC/PCA@MWCNT-Ni(OH)2 sensor represents a facile synthesis method of obtaining the hybrid nanomaterial and a low-cost approach to electrochemical glucose measurement in real samples (human serum, human blood).