Construction of ternary Au@GO coupled with poly-l-ethionine nanocomposite as a robust platform for electrochemical recognition of uric acid in diabetic patients

An ultra trace electrochemical detection of uric acid in diabetic patients is reported based on ternary composite consisting of gold nanoparticles (Au) @ graphene oxide coupled with poly-L-ethionine (Au@GO-PEION NCs). An electrochemical polymerization process is employed for the fabrication of Au@GO-PEION NCs and the formation was confirmed by various spectroscopic techniques including XRD, FT-IR, Raman, SEM and HR-TEM. The Au@GO-PEION NCs modified GCE demonstrates high selectivity and sensitivity towards uric acid (UA) in the existence of other interfering compounds under optimal conditions. During the interaction, UA was oxidized and then decomposed into allantoin which was not stable for longer time. As a result, cathodic peak current has not been observed in cyclic voltammogram and the mechanism for the oxidation of UA was established from the acquired anodic peak current. The fabricated Au@GO-PEION/GCE sensor demonstrates the low level recognition of 4.0 nM with 0.001 - 170 mu M for a linear dynamic range in differential pulse voltammetry. It shows long-time stability and good selectivity due to the synergistic effect of Au@GO coupled with PEION. For the realistic purpose, real sample analysis was executed with human urine and blood serum samples (diabetic patients), shows tremendous recovery. These results suggest that Au@GO-PEION/GCE sensor has a good reliability and open a new vision to develop novel electrode in sensing and electro-catalytic applications.