title: Diamond nanowires for highly sensitive matrix-free mass spectrometry analysis of small molecules.
abstract: This paper reports on the use of boron-doped diamond nanowires (BDD NWs) as an inorganic substrate for matrix-free laser desorption/ionization mass spectrometry (LDI-MS) analysis of small molecules. The diamond nanowires are prepared by reactive ion etching (RIE) with oxygen plasma of highly boron-doped (the boron level is 10(19) B cm(-3)) or undoped nanocrystalline diamond substrates. The resulting diamond nanowires are coated with a thin silicon oxide layer that confers a superhydrophilic character to the surface. To minimize droplet spreading, the nanowires were chemically functionalized with octadecyltrichlorosilane (OTS) and then UV/ozone treated to reach a final water contact angle of 120°. The sub-bandgap absorption under UV laser irradiation and the heat confinement inside the nanowires allowed desorption/ionization, most likely via a thermal mechanism, and mass spectrometry analysis of small molecules. A detection limit of 200 zeptomole for verapamil was demonstrated.
authors.affiliation: Institut de Recherche Interdisciplinaire (IRI-CNRS-3078), Université Lille1, Parc scientifique de la haute borne, 50 Avenue de Halley, 59658, Villeneuve d'Ascq, France. yannick.coffinier@iri.univ-lille1.fr
authors.forename: Yannick
authors.initials: Y
authors.lastname: Coffinier
authors.forename: Sabine
authors.initials: S
authors.lastname: Szunerits
authors.forename: Hervé
authors.initials: H
authors.lastname: Drobecq
authors.forename: Oleg
authors.initials: O
authors.lastname: Melnyk
authors.forename: Rabah
authors.initials: R
authors.lastname: Boukherroub
mesh_terms: D001895:Boron / Q000737:chemistry; D018130:Diamond / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000032:analysis; D012825:Silicon / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010455:Peptides; D018130:Diamond; D001895:Boron; D012825:Silicon