▎ 摘　　要

A very sensitive electrochemical sensor has been developed by modification of glassy carbon electrode (GCE) with graphene (GRP) and bismuth (III) oxide (Bi2O3) nanoparticles. The electrochemical behavior of Tranexamic acid was studied at GRP/GCE and Bi2O3/GCE using cyclic and square-wave voltammetric techniques. A well defined oxidation peak was observed in Britton-Robinson (BR) buffered solution. GRP/GCE and Bi2O3/GCE showed higher current response as compared to bare GCE. Electrochemical impedance spectra showed reduction of charge transfer resistance and higher electrocatalytic behavior of the sensors. The morphological characteristics of GRP and Bi2O3 nanoparticles were studied by atomic force microscopy (AFM). GRP/GCE showed a linear response for Tranexamic acid over the concentration range of 40-400 mu g/mL with the detection limit 16.57 mu g/mL. Variation of scan rate revealed that the electrode process is diffusion controlled. Moreover electrode dynamics parameters were calculated and a possible reaction mechanism has been deduced. This method was employed for quantification of Tranexamic acid in different pharmaceutical formulations. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.020210jes] All rights reserved.