title: Electrospray ion beam deposition of clusters and biomolecules.
abstract: An ion beam source using electrospray ionization is presented for nondestructive vacuum deposition of mass-selected large organic molecules and inorganic clusters. Electrospray ionization is used to create an ion beam from a solution containing the nanoparticles or molecules to be deposited. To form and guide the ion beam, radio frequency and electrostatic ion optics are utilized. The kinetic energy distribution of the particles is measured to control the beam formation and the landing process. The particle mass-to-charge ratio is analyzed by in situ time-of-flight mass spectrometry. To demonstrate the performance of the setup, deposition experiments with gold nanoclusters and bovine serum albumin proteins on graphite surfaces were performed and analyzed by ex situ atomic force microscopy. The small gold clusters are found to form three-dimensional agglomerations at the surface, preferentially decorating the step edges. In contrast, bovine serum albumin creates two-dimensional fractal nanostructures on the substrate terraces due to strong intermolecular interactions.
authors.affiliation: Max-Planck-Institute for Solid State Research, Nanoscale Science Department, Heisenbergstr. 1, 70569 Stuttgart, Germany. s.rauschenbach@fkf.mpg.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Rauschenbach
authors.forename: Frank L
authors.initials: FL
authors.lastname: Stadler
authors.forename: Eugenio
authors.initials: E
authors.lastname: Lunedei
authors.forename: Nicola
authors.initials: N
authors.lastname: Malinowski
authors.forename: Sergej
authors.initials: S
authors.lastname: Koltsov
authors.forename: Giovanni
authors.initials: G
authors.lastname: Costantini
authors.forename: Klaus
authors.initials: K
authors.lastname: Kern
mesh_terms: D001704:Biopolymers / Q000737:chemistry; D003460:Crystallization / Q000379:methods*; D017979:Gold Colloid / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013499:Surface Properties
chemical_list: D001704:Biopolymers; D017979:Gold Colloid; D046911:Macromolecular Substances; D012710:Serum Albumin, Bovine