Sensitive Spectrophotometric Detection of Dopamine, Levodopa and Adrenaline Using Surface Plasmon Resonance Band of Silver Nanoparticles

A simple and effective procedure is proposed for spectrophotometric determination of catecholamines; Dopamine (1), L-Dopa (2) and Adrenaline (3). It was found that the reduction of Ag(+) to silver nanoparticles (Ag-NPs) by these catecholamines in the presence of polyvinylpyrrolidone (PVP) as a stabilizing agent produced very intense surface plasmon resonance peak of Ag-NPs. The plasmon absorbance of the Ag-NPs allows the quantitative spectrophotometric detection of the catecholamines. The calibration curves derived from the changes in absorbance at lambda = 440 nm were linear with concentration of Dopamine, Levodopa and Adrenaline in the range of 3.2x10(-6)-2.0x10(-5) M, 1.6x10(-7) - 1.0x10(-5) M, 1.5x10(-6)-4.0x10(-5) M, respectively. The detection limits (3 sigma) were 1.2x10(-6) M, 8.6 x 10(-8) M, 9.7 x 10(-7) M for the Dopamine, L-Dopa and Adrenaline, respectively. The method was applied successfully to the determination of catecholamines in Ringer's injection serum.