Design of a New Non-enzymatic Sensor Based on a Substituted A2BO4+δ Perovskite for the Voltammetric Detection of Glucose

Instant determination of glucose levels is necessary to monitor the treatment of diabetes. The next generation of electrochemical sensors aims to eliminate the use of enzymes because of their lack of stability and the complex procedure to immobilize them on the electrode. In this paper Pr(1.92)Ba(0.08)Ni0.95Zn0.05O4+delta perovskite, a A(2)BO(4+delta) type, was tested, for the first time for non enzymatic detection of glucose. It was synthesized by a sol-gel method. The obtained crystallized powder was structurally characterized by XRD, morphologically characterized by SEM and EDX and electrochemically characterized. A monoclinic crystallographic system was formed. The presence of Pr2O3 during synthesis and calcination is in agreement with the formation of defects in the crystalline network and the disproportionation of Ni-III sites into Ni-II and Ni-IV, due to the substitution of Pr by Ba. The oxido-reduction of Ni-II sites is observed by cyclic voltammetry. The electrocatalytic oxidation of glucose through the electrooxidized Ni-II site was observed on a gold electrode, at 481 mV. The analytical performance of this glucose sensor is good in comparison to previously published ABO(3) perovskite modified electrodes, in terms of dynamic range (1.5 mu M-7000 mu M) and detection limit (0.5 mu M). Its application to human serum shows that there is no interference for glucose detection.