Non-enzymatic screen printed sensor based on Cu2O nanocubes for glucose determination in bio-fermentation processes

A non-enzymatic electrochemical sensor based on cuprous oxide nanocubes (Cu2O-NC) has been developed. Cu2O-NC samples have been synthesized using a wet precipitation technique under different precipitation temperatures (25 and 60 °C). The samples were characterized by XRD (X-ray Diffraction), UV–visible Diffuse Reflectance Spectroscopy (UV–Vis DRS) and Scanning Electron Microscopy (SEM). Screen-printed carbon electrodes (SPCE) have been modified by casting the synthesized Cu2O-NC. The fabricated Cu2O-NC-SPCE sensor prepared at 25 °C provided the best sensing performance toward glucose, with a sensitivity of 1040 μA/mM cm−2 in the linear range from 0.007 to 4.5 mM, and a detection limit of 3.1 μM (S/N = 3). Cu2O-NC-SPCE electrodes were also evaluated for the amperometric determination of glucose. Testing results showed a satisfactory stability toward glucose sensing and selectivity against other sugars and ethanol, suggesting that the SPCE modification with Cu2O-NC could be a simple way to fabricate inexpensive and reliable sensors to monitor glucose in bio-fermentation processes.