Highly sensitive non-enzymatic glucose sensor with copper oxide nanoparticle impregnated mesoporous silica

Abstract

Cuprous oxide (Cu2O) nanoparticles at a loading of 33.5 wt.% were impregnated in amine-functionalized mesoporous silica (NH2-SBA-15) particles, by an in situ chemical reduction method. Subsequently, Cu2O-NH2-SBA-15 hybrid was used as a modifier of glassy carbon electrode (GCE) for making a non-enzymatic glucose sensor. The optimum composition of the modifier on the GCE surface (0.47 mg Cu in Cu2O-NH2-SBA-15/cm2 surface area of GCE) resulted in a wide linearity range (0.2–15 mM glucose) and a high sensitivity of 438.3 µAcm−2 mM−1, due to the high loading of Cu2O in NH2-SBA-15 host. Furthermore, glucose was detected both in normal range (5 mM) and in hypoglycaemic range (2 mM), selectively in presence of concentrations of interfering species typically found in the normal blood, such as sodium chloride (142 mM), potassium chloride (3.7 mM), urea (4.7 mM) and ascorbic acid (0.05 mM). The response time was also less than 5 s. Therefore, it achieved the desirable sensor characteristics, like linearity, sensitivity, selectivity, and speed of response. This better performance of the sensor is mainly attributed to a high electrocatalytic activity of Cu2O nanoparticles towards glucose.