title: Photo-induced enhanced Raman spectroscopy for universal ultra-trace detection of explosives, pollutants and biomolecules.
abstract: Surface-enhanced Raman spectroscopy is one of the most sensitive spectroscopic techniques available, with single-molecule detection possible on a range of noble-metal substrates. It is widely used to detect molecules that have a strong Raman response at very low concentrations. Here we present photo-induced-enhanced Raman spectroscopy, where the combination of plasmonic nanoparticles with a photo-activated substrate gives rise to large signal enhancement (an order of magnitude) for a wide range of small molecules, even those with a typically low Raman cross-section. We show that the induced chemical enhancement is due to increased electron density at the noble-metal nanoparticles, and demonstrate the universality of this system with explosives, biomolecules and organic dyes, at trace levels. Our substrates are also easy to fabricate, self-cleaning and reusable.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: Sultan
authors.initials: S
authors.lastname: Ben-Jaber
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: William J
authors.identifier: 0000-0002-9829-2683
authors.initials: WJ
authors.lastname: Peveler
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: Raul
authors.initials: R
authors.lastname: Quesada-Cabrera
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ, UK.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Cortés
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sotelo-Vazquez
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: Nadia
authors.initials: N
authors.lastname: Abdul-Karim
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ, UK.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK.
authors.forename: Ivan P
authors.initials: IP
authors.lastname: Parkin
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D053834:Explosive Agents / Q000032:analysis*; D005947:Glucose / Q000032:analysis*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D053834:Explosive Agents; D005947:Glucose