title: Functionalization of silicon nanowire arrays by silver nanoparticles for the laser desorption ionization mass spectrometry analysis of vegetable oils.
abstract: In this work, novel hybrid nanostructured surfaces, consisting of dense arrays of silicon nanowires (SiNWs) functionalized by Ag nanoparticles (AgNP/SiNWs), were used for the laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) analysis of some typical unsaturated food components (e.g. squalene, oleic acid) to assess their MS performance. The synthesis of the novel platforms is an easy, cost-effective process based on the maskless wet-etching preparation at room temperature of SiNWs followed by their decoration with AgNPs, produced by pulsed laser deposition. No particular surface pretreatment or addition of organic matrixes/ionizers was necessary. Moreover, oil extracts (e.g. extra virgin olive oil, peanut oil) could be investigated on AgNP/SiNWs surfaces, revealing their different MS profiles. It was shown that such substrates operate at reduced laser energy, typically generating intense silver cluster ions and analyte adducts. A comparison with bare SiNWs was also performed, indicating the importance of AgNP density on NW surface. In this case, desorption/ionization on silicon was invoked as probable LDI mechanism. Finally, the influence of SiNW length and surface composition on MS results was assessed. The combination of typical properties of SiNWs (hydrophobicity, antireflectivity) with ionization ability of metal NPs can be a valid methodology for the further development of nanostructured surfaces in LDI-TOF MS applications. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Dipartimento di Chimica, Università degli Studi Bari 'Aldo Moro', Via E. Orabona 4, 70126, Bari, Italy.
authors.forename: Rosaria Anna
authors.identifier: http://orcid.org/0000-0001-8033-098X
authors.initials: RA
authors.lastname: Picca
authors.affiliation: Dipartimento di Chimica, Università degli Studi Bari 'Aldo Moro', Via E. Orabona 4, 70126, Bari, Italy.
authors.forename: Cosima Damiana
authors.initials: CD
authors.lastname: Calvano
authors.affiliation: CNR-IPCF, Istituto per i Processi Chimico-Fisici, V. le F. Stagno D'Alcontres 37, 98158, Messina, Italy.|MATIS CNR-IMM, Istituto per la Microelettronica e Microsistemi, Via Santa Sofia 64, 95123, Catania, Italy.
authors.forename: Maria Josè
authors.initials: MJ
authors.lastname: Lo Faro
authors.affiliation: CNR-IPCF, Istituto per i Processi Chimico-Fisici, V. le F. Stagno D'Alcontres 37, 98158, Messina, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Fazio
authors.affiliation: CNR-IPCF, Istituto per i Processi Chimico-Fisici, V. le F. Stagno D'Alcontres 37, 98158, Messina, Italy.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Trusso
authors.affiliation: Dipartimento di Energia and Center for NanoEngineered Materials and Surfaces-NEMAS, Politecnico di Milano, Milano, Italy.
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Ossi
authors.affiliation: Dipartimento di Scienze matematiche e informatiche, scienze fisiche e scienze della terra, Università degli Studi di Messina, Messina, Italy.
authors.forename: Fortunato
authors.initials: F
authors.lastname: Neri
authors.affiliation: MATIS CNR-IMM, Istituto per la Microelettronica e Microsistemi, Via Santa Sofia 64, 95123, Catania, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: D'Andrea
authors.affiliation: CNR-IPCF, Istituto per i Processi Chimico-Fisici, V. le F. Stagno D'Alcontres 37, 98158, Messina, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Irrera
authors.affiliation: Dipartimento di Chimica, Università degli Studi Bari 'Aldo Moro', Via E. Orabona 4, 70126, Bari, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Cioffi
mesh_terms: D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010938:Plant Oils / Q000032:analysis*; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D010938:Plant Oils; D012834:Silver; D012825:Silicon
keywords: DIOS; SALDI-MS; food analysis; nanomaterial; silicon nanowire; silver; unsaturated bonds