Synthesis of Copper Nanostructures for Non-Enzymatic Glucose Sensors via Direct-Current Magnetron Sputtering

Abstract

In this paper, Cu nanocolumnar structure electrodes are synthetized using a clean and easy-to-scale-up direct-current magnetron sputtering (DC-MS) technique for non-enzymatic glucose sensing. The nanocolumnar structure increases the active surface area of the deposit, with the nanocolumns showing a mean size diameter of 121.0 nm ± 27.2 and a length of 2.52 µm ± 0.23. A scanning transmission electron (STEM) analysis shows the presence of Cu and a small amount of Cu2O. The behavior of the electrodes in alkaline environments and the electrochemical affinity of the Cu nanocolumns (CuNCs) towards the electro-oxidation of glucose are investigated using cyclic voltammetry (CV). After performing CV in NaOH solution, the columnar structures present corrosion products containing Cu2O, as revealed by STEM and X-ray diffraction (XRD) analyses. The amperometric responses of the CuNCs to the successive addition of glucose show a linear range up to 2 mM and a limit of detection of 5.2 µM. Furthermore, the electrodes are free from chloride poisoning, and they are insensitive to dopamine, uric acid, ascorbic acid, and acetaminophen at their physiological concentrations.

Porous Copper Oxide Thin Film Electrodes for Non-Enzymatic Glucose Detection

“…The sensor response showed a very small response loss, lower than 5% after this period, confirming the excellent stability of the copper thin film deposited on the ITO electrode and its potential for further implementations in industrial and analytical applications. These results demonstrate the good electrocatalytic properties of the sensor with a low limit of detection and excellent sensitivity, better than previous values reported in the literature [19,22,32,[34][35][36][37][38][39][40][41][42][43][44][45] (see Table 1). The effect of other similar sugars (sucrose, lactose, and fructose) and common reducing agents (uric acid and ascorbic acid) found in biological and analytical matrixes were assessed.…”

Development of Thin Film Fabrication Using Magnetron Sputtering

“…Metallic nano-and micro-structures are used in biological applications. They have been used in enzyme-free glucose detection and utilized as the surface substrates of self-assembled molecular films [7,8]. They have also been used to produce the capacitance switch of radio frequency microelectromechanical systems (RF MEMS), which is commonly used for ferroelectric electrodes and high dielectric components, or electrodes for human-machine interfaces, electronic skins, and flexible displays [9][10][11][12].…”