Electrochemical behavior of a cation-exchange resin modified with copper ions on non-enzymatic glucose determination

Abstract

Currently, the search for non-biological materials that are able to oxidize glucose with good electrochemical response is very desired. In this work, we describe the use of a cation-exchange resin (Amberlite IR 120H) for Cu(II) ions incorporation and its application for a sensitive non-enzymatic glucose electrochemical sensor. The quantification is performed by amperometric measurements based on the high electrocatalytic activity of Cu(III), yielded on the electrode surface in alkaline solution. The proposed sensor was characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy analysis (EDS) and thermogravimetric analysis (TGA). Under optimized conditions, the proposed sensor showed a good accuracy and robustness and exhibit a linear dynamic range for glucose solutions from 5.0 μmol L−1 to 1.0 mmol L−1 and a limit of detection (LOD) of 1.8 μmol L−1, with a sensitivity 27-fold higher than the unmodified electrode. Human blood plasma samples of three healthy volunteers were evaluated by the proposed method and showed a good agreement with a standard clinical method in a confidence level of 95%.