Glucose sensors are relevant for use in several fields including healthcare and food industry. In this context, non-enzymatic glucose sensing based on the direct catalytic oxidation of glucose represent the “fourth generation of glucose sensor technology”. Ni material is one of the most investigated since allows the direct electro catalytic oxidation of glucose by means of the redox couple Ni3+/Ni2+ under alkaline medium. In this contribution we present a novel miniaturized three planar electrodes device integrating Ni layer on working electrode. In this contribution, we have developed a miniaturized three-planar electrode device integrating a working electrode made of Nickel (thickness 10 nm) for non-enzymatic glucose detection. The device exhibited good response towards glucose detection on human blood and urine samples. The silicon electrochemical device has been manufactured using the VLSI technology on a 6″ silicon substrate, it is composed by: 1) electrochemical silicon chip, containing 4 cells with three planar microelectrodes, 2) Heater and temperature sensor chip to perform measurement at high temperature, 3) plastic polycarbonate structures to form 4 reaction chambers (volume 22μl) and 4) plastic holder for device handling. The device has been characterized in sensitivity finding this parameter decreases with decreasing the electrolyte pH, with still some activity also at the physiological pH of 7.4. Extensively testing with real samples (fresh blood, saliva and urine) has been also proved. Glucose sensitivity in biocompatible PBS at different pH was evaluated. The results clearly indicate as expected an increasing of sensitivity with the pH increasing, with a maximum value of sensitivity at pH 13.0. At pH 11.2 (still compatible with human sample) a sensitivity of about 40 μA mM-1 cm-2 was found. Glucose on Human Blood Non-enzymatic glucose sensing on human blood was performed by amperometric experiement at a fixed potential (0.54 V), in PBS at pH 11.2. Glucose sensing with saliva (pretreated with buffer precipitation) was performed by amperometric experiement at a fixed potential (0.54 V) at pH 13.0.
Iwu, K. O., Lombardo, A., Sanz, R., Scirè, S., & Mirabella, S. (2016). Facile synthesis of Ni nanofoam for flexible and lowcost nonenzymatic glucose sensing. Sensors and Actuators B, 224(2016), 764–771.
Petralia, S., Castagna, M. E., Cappello, E., Puntoriero, F., Trovato, E., Gagliano, A. and Conoci, S., (2015) Sensing and bio-sensing research 6, 90–94.
Petralia S., Mirabella S., Strano V. e Conoci S. A Miniaturized Electrochemical System Based on Nickel Oxide Species for Glucose Sensing Applications. Bionanoscience (2017) (2017) 7, 58-63.