Synthesis and characterization of a dinuclear Schiff base complex and its composite with reduced graphene oxide for the sensitive detection of uric acid in human urine

In this study, we have fabricated electrochemical sensors utilizing an innovative dinuclear Schiff base complex based on nickel metal center with 3,3′-((1E,1′E)-(1,3-phenylene bis (azaneylylidene))bis(methaneylylidene))bis(benzene-1,2-diol) or PD ligand to form Ni2PD2 complex and reduced graphene oxide (RGO) to achieve sensitive detection of uric acid in human urine samples. The synthesis of Ni2PD2/RGO composite involved the complexation of the PD ligand with Ni2+ ions, which were integrated with RGO and subsequently applied on the surface of a glassy carbon electrode (GCE). According to the findings of electrochemical studies, Ni2PD2/RGO/GCE exhibited a linear response for uric acid concentrations ranging from 1 to 110 µM, with a limit of detection of 0.2 µM and a limit of quantification of 1 µM. Furthermore, the developed sensor demonstrated excellent stability and reproducibility with %RSD values below 5 %. This developed sensor demonstrated notable selectivity in the presence of interfering species, including K+, Cl−, Mg2+, ascorbic acid, dopamine, and urea, achieving an acceptable percentage recovery. The developed sensor was subsequently utilized to assess the uric acid concentration in human urine samples, demonstrating no statistically significant difference compared to commercial kit devices when analyzed at a 95 % confidence interval. This study underscores the potency of Ni2PD2/RGO-modified GCE as a noteworthy sensing platform for detecting uric acid, demonstrating considerable potential for practical applications.