Graphene oxide functionalized organosilanes for electrochemical detection of uric acid in urine and water

The development of a sensitive molecular probe for recognition of uric acid is imperative because of diseases caused from change in its normal level. In the present article, new nanocomposites are developed based on graphene oxide (GO) functionalized organosilanes and applied for electrochemical detection of uric acid using GO-Silane/Glassy Carbon Electrode (GCE). Firstly, Isoindolone tethered organosilanes are synthesized by inserting amino phenol into pthallic anhydride followed by azide-alkyne click reaction catalyzed by [CuBr (PPh3)3]. The presence of silane unit helped in the extension of this molecular system in the material field and the prepared organosilanes have been grafted over the graphene oxide surface to get the desired probe for uric acid. The newly synthesized compounds have been well characterized by Infrared Spectroscopy (IR), Nuclear Magnetic Resonance (1H and 13C NMR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) and mass spectral analysis. Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) are used to evaluate the electrochemical signal of the prepared GO-Silane/GCE electrode. The results obtained shows excellent selectivity for uric acid against different species with a low detection limit of 65.7 nM in the linear range 2.5 μM to 80.0 μM. Further, the outcome of the work suggests high specificity of the current GO-silane based receptor for uric acid in the presence of different interfering ions. Moreover, the real sample analysis of the present organosilane-based receptor in urine and water pave the way for its practical applicability.