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 λ = 440 nm were linear with concentration of Dopamine, Levodopa and Adrenaline in the range of 3.2×10−6− 2.0×10−5 M, 1.6×10−7 − 1.0×10−5 M, 1.5×10−6− 4.0×10−5 M, respectively. The detection limits (3σ) were 1.2×10−6 M, 8.6 ×10−8 M, 9.7 ×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.