Cobalt sensitive optic sensor production using silver nanoparets

Keywords: Cobalt ions, silver nanoparticles, cysteine, glutathione Silver nanoparticles are often used in spectroscopic studies because of their surface plasmon resonance properties and therefore absorbing certain wavelengths of light. Rather than the use of nanoparticles as a bare particles, by modifying with different organic molecules, they can be used in many different areas. As mentioned in this study, one of the molecules used for modification is reduced glutathione (γ-glutamylcysteinyl- glycine GSH) molecules. In this study, a triple system was used to determine the Co (II) ions. These are modified silver nanoparticles, cysteine and metal ions. For the metal ion determination, a certain amount of those solutions should be mixed. The base of the triple system is the modified silver nanaoparticles. Silver nanoparticles were obtained by reducing the silver in silver nitrate solution by adding NaBH4 (sodium borohydride). GSH was added to the medium to prevent growth of the silver nanoparticles. Modified silver nanoparticles were added to the medium by adding cysteine and metal ions, and metal ion concentration was determined from the UV spectrum of the obtained complex. For the determination of the metal ion concentration, the first derivatives of the every single spectra were taken and a calibration graph was prepared. The concentration of unknown sample was determined depending on the prepared calibration graph. The sensetivity of the method was tested in the presence of other metal ions. To observe the matrix effect from solution, the cobalt ion concentration was determined in cobalt spiked tap water.