title: Two-dimensional microfabricated sources for nanoelectrospray.
abstract: The idea of a novel two-dimensional (2D) nanoelectrospray ionization emitter tip with the shape of a nib is explored here. This novel planar design is studied as an alternative to the needle-like standard emitter tips that suffer from a lack of reproducibility and robustness and from an inherent incompatibility with high-throughput analysis. The composition of the micro-nib sources is analogous to the working of a simple fountain pen, with a liquid reservoir linked to a micro-nib tip from which the sample is electrosprayed via a capillary slot. The micro-nib prototypes described here were fabricated using microtechnology techniques and using the epoxy-based negative photoresist SU-8. The resulting free-standing micro-nib structure was supported by a silicon wafer. We present here two series of such micro-nib sources, the latter series exhibiting improved characteristics such as a 8 micro m source width of the nib tip. They were tested in mass spectrometry experiments on an ion trap mass spectrometer (LCQ Deca XP+, Thermo Finnigan) using standard peptide samples having concentrations down to 1 micro M and with a high voltage (HV) supply around 1 kV for the second series of micro-nib sources. In addition to the stability of the spray, the obtained mass spectra showed the reliability of these sources for peptide analysis; the signal of the spectra was as intense and the signal-to-noise ratio (S/N) as high as that obtained with the use of standard emitter tips.
authors.affiliation: Laboratoire de Chimie Organique et Macromoléculaire, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Le Gac
authors.forename: Steve
authors.initials: S
authors.lastname: Arscott
authors.forename: Cécile
authors.initials: C
authors.lastname: Cren-Olivé
authors.forename: Christian
authors.initials: C
authors.lastname: Rolando
mesh_terms: D006096:Gramicidin / Q000032:analysis; D008904:Miniaturization / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation*
chemical_list: D006096:Gramicidin