NAFION stabilized silver nanoparticles modified electrodes: characterization and use in electroanalysis

Spherical silver nanoparticles (10-30 nm) were synthesized modifying a published procedure1, and confirmed by TEM and UV-vis analysis. The Ag nanoparticles were used to modify Glassy Carbon (GC) Electrodes depositing onto the GC support a suspension of the nanomaterials in Nafion®. Electrodes were morphologically characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). Stability in air and in solution and repeatability were evaluated and their electrochemical properties, compared with those of bare glassy carbon and Nafion-modified glassy carbon electrodes, were studied with Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) measurements, using [Ru(NH3)6]Cl3 as model probe molecule. The modified electrodes show promising electroanalytical performances with very high current densities, probably due to the increase of the effective surface area, to a formation of a random array of nanoparticles on the Nafion® three-dimensional substrate with intermediate diffusional behaviour between planar and convergent2-3, and to a very small double layer capacitance. Applications exploiting the electrocatalytic properties of Ag for the detection of a model simple chlorinated compound (dichloromethane) and a more complex organic chlorinated compound (halothane) are presented. References [1] Z. Shervani, Y. Ikushima, M. Sato, H. Kawanami, Y. Hakuta, T. Yokoyama, T. Nagase, H. Kuneida, K. Aramaki, Colloid Polym Sci, (2008), 286, 403. [2] F.W. Campbell, R.G. Compton, Anal Bioanal Chem, (2010), 396, 241. [3] S.J. Xing, H. Xu, J.S. Chen, G.Y. Shi, L.T. Jin, J Electroanal Chem, (2011), 652, 60.