title: Electrically Excited Plasmonic Nanoruler for Biomolecule Detection.
abstract: Plasmon-based sensors are excellent tools for a label-free detection of small biomolecules. An interesting group of such sensors are plasmonic nanorulers that rely on the plasmon hybridization upon modification of their morphology to sense nanoscale distances. Sensor geometries based on the interaction of plasmons in a flat metallic layer together with metal nanoparticles inherit unique advantages but need a special optical excitation configuration that is not easy to miniaturize. Herein, we introduce the concept of nanoruler excitation by direct, electrically induced generation of surface plasmons based on the quantum shot noise of tunneling currents. An electron tunneling junction consisting of a metal-dielectric-semiconductor heterostructure is directly incorporated into the nanoruler basic geometry. With the application of voltage on this modified nanoruler, the plasmon modes are directly excited without any additional optical component as a light source. We demonstrate via several experiments that this electrically driven nanoruler possesses similar properties as an optically exited one and confirm its sensing capabilities by the detection of the binding of small biomolecules such as antibodies. This new sensing principle could open the way to a new platform of highly miniaturized, integrated plasmonic sensors compatible with monolithic integrated circuits.
authors.affiliation: Department of Nanobiophotonics and ‡Department of Quantum Detection, Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Dathe
authors.affiliation: Department of Nanobiophotonics and ‡Department of Quantum Detection, Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Ziegler
authors.affiliation: Department of Nanobiophotonics and ‡Department of Quantum Detection, Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Hübner
authors.affiliation: Department of Nanobiophotonics and ‡Department of Quantum Detection, Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fritzsche
authors.affiliation: Department of Nanobiophotonics and ‡Department of Quantum Detection, Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Stranik
mesh_terms: D004560:Electricity; D053768:Metal Nanoparticles; D008670:Metals; D012710:Serum Albumin, Bovine; D020349:Surface Plasmon Resonance
chemical_list: D008670:Metals; D012710:Serum Albumin, Bovine
keywords: Plasmonic nanoruler; biomolecule detection; electrical excitation; inelastic tunneling; nanoparticle