Measuring of metanephrine by UV-Vis peak of surface absorption Plasmon resonance of silver nanoparticles by response surface methodology

A simple and low-cost spectrophotometry method was proposed based on resonance Plasmon peak of silver nanoparticles for measurement of metanephrine(MN) drug. This method was based on reducing property of metanephrine and it was founded that this compound reduces silver ions in presence of polyvidone (PVP) as stabilizer compound. In this condition the formed silver nanoparticles show a localized surface plasmon resonance (LSPR) peak of about 423 nm. The resulted nano-particles were analyzed by transmission electron microscope (TEM) technique and nanoparticles size was estimated to be maximum of 200nm. Furthermore, realized that the absorption of solution depends on concentration of metanephrine and the maximum of absorption was found at 〖AgNO〗_3 concentration of 1.53 mM, NaOH concentration of 4.10 mM, 〖NH〗_3 concentration of 2.51 mM and 1.15 ml of PVP. Also, the proposed method showed a good linear relationship than MN concentration in the range of 2.5-20 µM and limit of detection was obtained as 0.6 µM for metanephrine. Finally, this method was used for measuring epinephrine in real samples and the acceptable results were obtained.