Simultaneous determination of guanosine and guanosine-5'-triphosphate in biological sample using gold nanoparticles modified indium tin oxide electrode.

A nanogold modified indium tin oxide (ITO) electrode was used for the simultaneous determination of guanosine and GTP at pH 7.2. The electrode exhibited an effective catalytic response towards their oxidation and lowered the oxidation potential of guanosine by approximately 120 mV and GTP by approximately 183 mV. Linear concentration curves were obtained for guanosine with a detection limit of 9.8 x 10(-8) M and 5.5 x 10(-8) M for GTP. The concentration of guanosine and GTP were also estimated in the human blood plasma samples using gold nanoparticles modified ITO electrode with good reproducibility.