A novel approach for electroanalytical determinations employing discharge of pseudocapacitor by electroactive species

In this paper, we introduce a novel approach for the detection of electroactive analytes by using oxidant species accumulated in pseudocapacitors surface. We demonstrated that pseudocapacitors can be quickly discharged when in contact with electroactive species. Thus, the variation of potential can be monitored during the discharging process and correlated with the analyte concentration. Based on this, two electroanalytical methods were proposed: continuous discharging detection and pulsed discharging detection. As a proof of concept, these methods were employed for glucose, fructose and sucrose detection using an ion chromatograph containing an electrochemical detector. Copper|cupric oxide in alkaline medium was used as the pseudocapacitive system. The obtained results proved to be very promising and the analytical curves showed good linearity in both methods. In addition, this novel approach for the detection of saccharides based on potential variation as a result of the discharging of the pseudocapacitor in contact with the analyte is very attractive because it does not require current reading. Therefore, our approach can be applied to other pseudocapacitive systems, opening new possibilities for several electroanalytical applications.