Sol-gel synthesis of cubic titanium dioxide nanoparticle using poly(ethylene glycol) as a capping agent: voltammetric simultaneous determination of uric acid and guanine.

Abstract

Titanium dioxide nanoparticles (NPs) were synthesized by a sol-gel method from hexafluorotitanic acid using poly(ethylene glycol) as a capping agent. The crystal structure and morphology of the NPs were characterized by X-ray diffraction, FESEM, and TEM. The NPs were used to modify a graphite paste electrode for simultaneous determination of uric acid (UA) and guanine (GU). The effect of calcination temperature on crystal structure and electrocatalytic activity was investigated. The electrochemical responses to UA and GU at bare GP, TiO2-350/GP, and TiO2-600/GP electrodes were compared. The DPV oxidation peaks of UA and GU were found to be strongest ataround 304 and 673mV, respectively, against Ag/AgCl reference electrode, and this arewell separated for effective simultaneous determination. UA and GU can be simultaneously determined by this method. Response is linear within the range 0.1-500μM and 0.1-40μM for UA and GU, respectively. The detection limits are 70nM for UA and 50nM for GU (at anS/N ratio of 3). The TiO2-600/GP electrode showed excellent analytical performance when analyzing spiked urine and serum samples. Graphical abstract A graphical representation of cubic TiO2 nanoparticle formation during hydrolysis through sol-gel process.