Utilization of AC Impedance Measurements for Electrochemical Glucose Sensing Using Glucose Oxidase to Improve Detection Selectivity

Abstract

The electrochemical detection of glucose using glucose oxidase (GOx) has been conducted by means of AC impedance measurements. In the absence of glucose, the Nyquist plots were straight line due to a reversible redox reaction involving the electron mediator. On the other hand, the Nyquist plots became a circular arc in the presence of glucose, and its radius decreased with an increase in the glucose concentration. The shape of the Nyquist plots were explained with assistance of numerical calculations. Since the reaction impedance due to direct oxidation of interfering species was significantly higher than that of glucose oxidation catalyzed by glucose oxidase, unfavorable influence from interfering species could be eliminated without needing a complicated sensor device. When ferrocenecarboxylic acid was used as an electron mediator, the calibration curve obtained from the Nyquist plots was not affected by the presence of ascorbic acid. Based on those findings, a sensing system, which has no interference from both ascorbic acid and uric acid, was fabricated by using [Os(bpy) 3 ]Cl 2 , which has a highly positive redox potential (0.65 V), as an electron mediator. A method to prepare calibration curves from AC impedance measurements with a fixed frequency was established so that this technique can be put to practical use.

Performance Assessment of a Perfluorosulfonic Acid‐type Membrane (i. e. Nafion™ 115) for an Enzymatic Fuel Cell

“…Electrical, ionic and mass transfer resistances can affectively be determined by using EIS . There are number of publications using electrochemical impedance spectroscopy method to study enzyme electrodes and microbial fuel cells . Jung and Hall applied EIS extensively to analyze catalytic response of GO x enzyme electrode in an organic salt .…”

“…and Kohma et al. reported an impedance simulation method and discussed the change in the shape of the electrochemical impedance spectra with the concentration gradient of the mediator on the electrode surface at each frequency . Samukawa et al.…”

Gold nanoparticle/nickel oxide/poly(pyrrole-N-propionic acid) hybrid multilayer film: Electrochemical study and its application in biosensing

“…The 3.6. Electrochemical impedance spectroscopy study of Ty based electrode (ITO/GNPs/NiO/poly(PPA)-Ty) EIS is a versatile technique describing the response of an electrochemical process taking place at the electrode solution interface [65]. It has been demonstrated that EIS measurements can provide significantly more sensitive responses than amperometric techniques for the detection of some biomolecules [66,67].…”

Elimination of Influence by Interference Substance on Amperometric Enzyme Biosensor Response Using Wavelet Transformation

“…In this case, if the cost of the membrane is expensive, the price of one biosensor tip may be very expensive. 8 Kuwabata et al [9][10][11] applied electrochemical impedance spectroscopy (EIS) to electrochemical glucose sensing without any selective permeable membranes. EIS is one of the nondestructive methods for measuring the current response to the application of sinusoidal AC voltage at various frequencies.…”