Visualization of gold clusters deposited on a dithiol self-assembled monolayer by tapping mode atomic force microscopy

Abstract Tapping mode atomic force microscopy (TM-AFM) was used to characterize individual gold clusters deposited on a 1,4-benzenedimethanethiol layer. Au n ( n =1–500) clusters were produced with a laser vaporization source and deposited with low kinetic energy (0.4 eV/atom). The free thiol group of the 1,4-benzenedimethanethiol layer gives rise to a large attractive force that inhibits reliable AFM probing of the sample with standard silicon tips. After etching the tip with hydrogen fluoride this interaction becomes repulsive and the image quality drastically improves. Tip–surface interaction measurements combined with an analysis of the cluster sizes reveal a configuration where clusters grow on top of the dithiol layer. The clusters are slightly deformed after impact and due to a strong sulfur–gold binding the cluster mobility on the layer is negligible.

[1]  Gregory M. Ferrence,et al.  Self-assembled monolayers of dithiols, diisocyanides, and isocyanothiols on gold: ‘chemically sticky’ surfaces for covalent attachment of metal clusters and studies of interfacial electron transfer , 1996 .

[2]  Jason Cleveland,et al.  Energy dissipation in tapping-mode atomic force microscopy , 1998 .

[3]  K. W. Hipps.  It's All About Contacts , 2001, Science.

[4]  Tian,et al.  Electronic conduction through organic molecules. , 1996, Physical review. B, Condensed matter.

[5]  T. Pradeep,et al.  Self-assembled Monolayers of 1,4-Benzenedimethanethiol on Polycrystalline Silver and Gold Films: An Investigation of Structure, Stability, Dynamics, and Reactivity , 1998 .

[6]  P. Sheng,et al.  Growth and characterization of Au clusters on alkanethiol self-assembled monolayers , 2000 .

[7]  Javier Tamayo,et al.  Interpretation of phase contrast in tapping mode AFM and shear force microscopy: a study of Nafion , 2001 .

[8]  R. P. Andres,et al.  Coulomb Staircase at Room Temperature in a Self-Assembled Molecular Nanostructure , 1996, Science.

[9]  Marcella Giovannini,et al.  Self-organized growth of nanostructure arrays on strain-relief patterns , 1998, Nature.

[10]  Andrés,et al.  Room-temperature Coulomb blockade from a self-assembled molecular nanostructure. , 1995, Physical review. B, Condensed matter.

[11]  F. Sbrana,et al.  Assembling thiolated gold nanoparticles in compact patterns: a transmission electron microscopy and scanning probe microscopy investigation , 2002 .

[12]  F. Schreiber.  Structure and growth of self-assembling monolayers , 2000 .

[13]  C. V. Haesendonck,et al.  Scanning probe microscopy investigation of gold clusters deposited on atomically flat substrates , 2003 .

[14]  K. Svensson,et al.  STM studies of passivated Au nanocrystals immobilised on a passivated Au(111) surface: ordered arrays and single electron tunnelling , 2000 .

[15]  P. Mélinon,et al.  Deposition of Au N clusters on Au(111) surfaces. I. Atomic-scale modeling , 2000 .

[16]  Nabil A. Amro,et al.  Precise Positioning of Nanoparticles on Surfaces Using Scanning Probe Lithography , 2003 .

[17]  John K. Tomfohr,et al.  Reproducible Measurement of Single-Molecule Conductivity , 2001, Science.

[18]  T. Ohgi,et al.  Au particle deposition onto self-assembled monolayers of thiol and dithiol molecules , 1998 .

[19]  Janos H. Fendler,et al.  Chemical Self-assembly for Electronic Applications , 2001 .

[20]  C. Binns.  Nanoclusters deposited on surfaces , 2001 .

[21]  P. Jensen.  Growth of nanostructures by cluster deposition: Experiments and simple models , 1999 .