Nickel/Copper bilayer-modified screen printed electrode for glucose determination in flow injection analysis

This work reports about the performance of a Ni/Cu-modified screen printed electrodes (SPE/Ni/Cu), prepared by physical vapor deposition (PVD) in an oblique angle configuration (OAD), for non-enzymatic glucose sensing applications. SPE/Ni/Cu electrodes showed an excellent reversibility and a catalytic behavior for detection of glucose that were controlled by the diffusion of reactants up to the active sites at the electrode surface. The study with a flow injection analysis (FIA) setup of the main experimental variables affecting the detection process has shown that the developed electrode system had an excellent glucose sensitivity of 1.04 AM1cm2 (R2:0.999), a linear response up to 1 mM, a limit of detection of 0.33 mM and a time of analysis of ca. 30 s per sample. The selectivity of the sensor was checked against various interferences, including ascorbic acid, uric acid, acetaminophen and other sugars, in all cases with excellent results. The feasibility of using this sensor for practical applications was successfully confirmed by determining the glucose concentration in different commercial beverages.
The financial support for the development of this work has been granted by the FEDER funds of the UE and the projects MAT2013‐40852‐R and MAT2016‐79866‐R from MINECO, 201560E055 from CSIC‐MINECO and RECUPERA2020 from MINECO‐“Fondo social Europeo”. Pedro Salazar thanks RECUPERA 2020 project for financial support.