Ultrasensitive and Highly Selective Ni₃Te₂ as a Nonenzymatic Glucose Sensor at Extremely Low Working Potential

Developing Nonenzymatic glucose biosensors has recently been at the center of attention owing to their potential application in implantable and continuous glucose monitoring systems. In this article, nickel telluride nanostructure with the generic formula of Ni₃Te₂ has been reported as a highly efficient electrocatalyst for glucose oxidation, functional at a low operating potential. Ni₃Te₂ nanostructures were prepared by two synthesis methods, direct electrodeposition on the electrode and hydrothermal method. The electrodeposited Ni₃Te₂ exhibited a wide linear range of response corresponding to glucose oxidation exhibiting a high sensitivity of 41.615 mA cm^-2 mM^-1 and a low limit of detection (LOD) of 0.43 μM. The hydrothermally synthesized Ni₃Te₂, on the other hand, also exhibits an ultrahigh sensitivity of 35.213 mA cm^-2 mM^-1 and an LOD of 0.38 μM. The observation of high efficiency for glucose oxidation for both Ni₃Te₂ electrodes irrespective of the synthesis method further confirms the enhanced intrinsic property of the material toward glucose oxidation. In addition to high sensitivity and low LOD, Ni₃Te₂ electrocatalyst also has good selectivity and long-term stability in a 0.1 M KOH solution. Since it is operative at a low applied potential of 0.35 V vs Ag|AgCl, interference from other electrochemically active species is reduced, thus increasing the accuracy of this sensor.