Nikoletta Molnár-Vörös1, Ilona Felhősi 1, Judit Telegdi1, Imre Dékány 2
1 Chemical Research Center of the Hungarian Academy of Sciences, Department of Surface Modification and Nanostructures
2 Department of Colloid Chemistry and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged
Surface functionalized gold nanoparticles with 2-10 nm diameter, stabilized by octanethiol, 8-Mercapto-1-octanol, 8-mercapto octanoic acid and 2-phenylethanethiol were prepared. The as prepared nanosols were characterized using TEM, UV-VIS, DLS, TG-DSC-(MS). The surface modified nanoparticles are forming stable dispersions in aromatic (toluene) or protic (ethanol) organic solvents. The concentrated gold dispersions were used for coating the surface of special interdigitated electrodes. Due to adsorption of different organic vapors, the interparticle distance increases, causing a significant increase in the resistance of the sensor, making it suitable for the detection of various organic volatiles. The interdigitated sensors coated with functionalized gold nanoparticles were placed in a vapor chamber in which the partial pressure of the organic vapors can be varied and the DC electric resistance of the sensors and the AC impedance were measured. It was found, that the sensor signal depends significantly from the concentration of the organic vapors.
1] N.L. Jarvis, R.R. Smardzewsk, A.W. Snow H. Wohltjen: Alkylthiol Stabilized Gold Nanoclusters for CB Detection
 M.Brust, M.Walker, D. Bethell, D.J.Schiffrin, R.Whyman, J. Chem. Soc. Chem. Commun, 1994, 801-802
 N.Molnár, R.Patakfalvi, I.Dékány, Coll. Surf. A, 2008, 329, 205.