Shell@Core Coaxial NiO@Ni Nanowire Arrays as High Performance Enzymeless Glucose Sensor

Abstract

Vertically aligned nanowire array based sensor platform that can monitor electro active species without the requirement of enzyme have received much attention lately. In particular, vertically aligned Ni nanowire arrays (NiNAE) have been found to have excellent catalytic activity toward carbohydrates. However, nickel oxidizes or corrodes in air, and this presents a question about its usefulness as a reliable and stable sensing materials. To address this problem, the authors have developed a vertically aligned co-axial nickel oxide-nickel nanowire array electrode (NiO@NiNAE) platform which can detect glucose without the presence of enzyme. The fabrication procedure is simple and catalytic activity toward glucose has been found to be excellent, this is attributed to the presence of stable NiO around the Ni nanowire. Details of morphological and electrochemical characterization of the sensor platform have been studied to evaluate the sensor performance. The sensitivity of NiNAE and NiO@NiNAE has been found to be 80.0 and 170.4 mC mM−1 cm−2, respectively. Under optimal detection conditions, the as prepared sensors exhibited linear behavior for glucose detection in the concentration up to 7 mM for both NiNAE and NiO@NiNAE with a limit of detection of 33 and 14 μM, respectively.