Non-enzymatic glucose detection via ordered 2D arrays of nickel and nickel chitosan nanowires

Glucose sensors play a vital role in the everyday healthcare needs of diabetic patients. However, glucose sensor cost and reliability, particularly regarding their standard functionalization with expensive and environmentally sensitive enzymes, remains a challenge. A method for the fabrication of nickel nanowire arrays (NWAs) coated with a thin layer of chitosan for the non-enzymatic detection of glucose is herein reported. The method is based on the electrodeposition of nickel into anodic aluminum oxide (AAO) templates, followed by a novel chitosan coating procedure. The nickel and nickel chitosan NWAs were characterized via electron microscopy, Raman spectroscopy, and electrochemical techniques. Electrochemical testing using cyclic voltammetry and chronoamperometry demonstrated that the chitosan coating enhanced the selectivity and stability of the electrochemical sensor for glucose detection, even in the presence of interfering species. Additionally, the coating improved the sensor's sensitivity by 46.39 % and expanded its linear detection range from 3.85 mM to 4.37 mM. The chitosan coating also helped to retain these characteristics even after exposure to physiologically accurate samples and prevented biofouling after exposure to proteins. This simple and robust glucose sensor paves the way for the fabrication of glucose sensors with a high linear range without the need for functionalization with traditional glucose detecting agents such as glucose oxidase.