Yttria-zirconia electrochemical sensor for the detection of tyrosine

A simple enzyme-free electrochemical sensor, based on modified yttria-doped zirconium oxide screen-printed carbon electrode (SPCE) has been developed for the determination of tyrosine (Tyr). Firstly, the morphology, microstructure and the electrochemical characteristics of commercial yttria-doped zirconium oxides with different yttria loading (0-40 mol. %) were reported. Cyclic voltammetry (CV) tests performed in phosphate buffer solutions (0.01 M PBS; pH = 7.4) in the absence and the presence of Tyr showed that the modified Zr8Y/ SPCE (containing 8 mol. % of yttria) exhibits better electrochemical properties compared to other electrodes investigated. Finally, the Zr8Y/SPCE sensor was tested for the detection of tyrosine by using the differential pulse voltammetry (DPV) method, providing a sensitivity of 0.140 & mu;A & mu;M- 1cm- 2 and a limit of detection (LOD) of 0.1 & mu;M (at S/N = 3). The performed study shows excellent results for tyrosine detection in a real food supplement sample. The calculated relative standard deviation (RSD) was 1.41 %. To our knowledge, this is the first device developed with a commercial yttria-doped zirconia nanomaterial for the electroanalytical determination of tyrosine.

Automated summary

A simple enzyme-free electrochemical sensor based on modified yttria-doped zirconium oxide screen-printed carbon electrode (SPCE) has been developed for the determination of tyrosine. The modified Zr8Y/SPCE with 8 mol.% of yttria exhibited better electrochemical properties compared to other electrodes. The sensor showed a sensitivity of 0.140 μA·μM-1cm-2 and a limit of detection (LOD) of 0.1 μM (at S/N = 3) for tyrosine detection.