title: Dielectrophoretic positioning of single nanoparticles on atomic force microscope tips for tip-enhanced Raman spectroscopy.
abstract: Tip-enhanced Raman spectroscopy, a combination of Raman spectroscopy and scanning probe microscopy, is a powerful technique to detect the vibrational fingerprint of molecules at the nanometer scale. A metal nanoparticle at the apex of an atomic force microscope tip leads to a large enhancement of the electromagnetic field when illuminated with an appropriate wavelength, resulting in an increased Raman signal. A controlled positioning of individual nanoparticles at the tip would improve the reproducibility of the probes and is quite demanding due to usually serial and labor-intensive approaches. In contrast to commonly used submicron manipulation techniques, dielectrophoresis allows a parallel and scalable production, and provides a novel approach toward reproducible and at the same time affordable tip-enhanced Raman spectroscopy tips. We demonstrate the successful positioning of an individual plasmonic nanoparticle on a commercial atomic force microscope tip by dielectrophoresis followed by experimental proof of the Raman signal enhancing capabilities of such tips.
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Leiterer
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.|Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Jena, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Deckert-Gaudig
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.|Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Jena, Germany.
authors.forename: Prabha
authors.initials: P
authors.lastname: Singh
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Wirth
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.|Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Jena, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Deckert
authors.affiliation: Leibniz Institute of Photonic Technology Jena (IPHT), Jena, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fritzsche
mesh_terms: D004586:Electrophoresis / Q000379:methods*; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods
chemical_list: D012834:Silver; D006046:Gold
keywords: Dielectrophoresis; Nanoparticle; Raman spectroscopy