Development of Nanostructured Enzymic Amperometric Biosensor based on Gold Nanoparticles for Detection of Pyruvate in Natural Samples

Abstract

The goal of this work was to create an enzymatic nanostructured-based amperometric biosensor for pyruvate detection in blood serum samples. The biosensor was prepared by electrodeposition of Au@CNTs nanocomposite on a glassy carbon electrode and immobilization of the pyruvate oxidase (PyOx) on nanocomposite (PyOx/Au@CNTs/GCE). The structural studies using XRD and SEM indicated the metallic Au NPs were effectively decorated on the CNTs surface and Au@CNTs nanocomposite electrodeposited on the GCE surface. EIS analyses also confirmed the covalent binding of PyOx molecules onto the Au@CNTs surface. CV, DPV and amperometry measurements showed that the PyOx/Au@CNTs/GCE had good specificity, sensitivity and stability to determination pyruvate, and a linear range of 10 to 480 μM, detection limit of 5 nM and sensitivity of 0.12482 μA/μM were obtained for the developed pyruvate biosensor. Moreover, comparison of the results obtained of developed biosensor to those of previously reported pyruvate biosensor systems demonstrated a comparable or better linear range and detection limit of PyOx/Au@CNTs/GCE that is associated with the synergistic catalytic effect of Au NPs and CNTs and immobilized PyOx molecules. The practicality and precision of the biosensor were examined for the determination level of pyruvate in blood serum of healthy adults as real samples and results showed good agreement between the amperometry and ELISA techniques, and also acceptable accuracy (RSD from 2.11% to 4.14%). These findings indicate that PyOx/Au@CNTs/GCE as a reliable pyruvate biosensor can be used for clinical diagnosis.