Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology LadkrabangAdvanced Materials Research Unit, Faculty of Science,King Mongkut's Institute of Technology LadkrabangPiboonbumpen Demonstration School, Faculty of Education,
Ekarat Detsri;Kanrayasiri Kamhom;Chatsuda Detsri
Unmodified gold nanoparticles(Au NPs) have been successfully synthesized by the reduction of tetrachloride gold(III)-) in the presence of sodium citrate based on the rapid microwaveassisted approach. The sodium citrate protected Au NPs were found to be selective and sensitive for the detection of dopamine. It was based on the aggregation change of the nanoparticles from random coil to hairpin structure upon the addition of dopamine concentration. The red shift of the plasmonic peak wavelength of Au NPs could be used for the detection of dopamine. The response to dopamine allows for a linear range from 10 to 125mg L-1(R2 = 0.9804) with a limit of detection(LOD) at a signal to noise ratio of 3 of 12.85 1.38 mg L-1. The colorimetric sensor was evaluated with 98.0 99.9 recovery of added dopamine in urine sample. The proposed sensor was successfully applied to the determination of dopamine in biological samples.