Paper Title
Development of a Portable Screen-Printed Graphene Electrode for Determination Total Gold Ions in Environments

A new electrochemical sensor using paper-based screen-printed graphene electrode (SPGE) was first developed here for the determination of gold ions in environmental waste water using square wave voltammetry. The procedure based on the reduction of gold ions at graphene electrode surface. The effects of basic experimental parameters on the response of the SPGE electrode were investigated to obtain the optimal operating conditions. Under the optimal conditions, a wide linear range of 1 - 200 mgL-1 (y = 0.5421x + 2.5461, R2=0.999) and limit of detection (at S/N = 3) of 0.05 mgL-1were received. In addition, this developed sensor provided high selectivity toward the reduction of gold ions without suffering from interferences. The proposed method has been successfully applied for the determination of Au ions in canal water sample (Saen Saep canal, Bangkok Thailand). The relative recovery and %RSD values were in the range of 92.77 – 107.51% and 2.17 – 4.15%, respectively. The results obtained can be compared with those of conventional methods (AAS or ICP-OES), however, the proposed sensor offers the advantages of fastness, simplicity, high sensitivity, and no requirement of complicated operational step. These approaches could be the alternative sensing for environmental filed monitoring. Keywords - Graphene Screen-Printed Electrode (SPGE), Gold Ions, Portable Sensor, Square Wave Voltammetry (SWV).