title: An open design microfabricated nib-like nanoelectrospray emitter tip on a conducting silicon substrate for the application of the ionization voltage.
abstract: This paper describes a novel emitter tip having the shape of a nib and based on an open structure for nano-electrospray ionization mass spectrometry (nanoESI-MS). The nib structure is fabricated with standard lithography techniques using SU-8, an epoxy-based negative photoresist. The tip is comprised of a reservoir, a capillary slot and a point-like feature, and is fabricated on a silicon wafer. We present here a novel scheme for interfacing such nib tips to MS by applying the ionization voltage directly onto the semi-conductor support. The silicon support is in direct contact with the liquid to be analyzed at the reservoir and microchannel level, thus allowing easy use in ESI-MS. This scheme is especially advantageous for automated analysis as the manual step of positioning a metallic wire into the reservoir is avoided. In addition, the analysis performance was enhanced compared with the former scheme, as demonstrated by the tests of standard peptides (gramicidin S, Glu-fibrinopeptide B). The limit of detection was determined to be lower than 10(-2) microM. Due to their enhanced performance, these microfabricated sources might be of great interest for analysis requiring very high sensitivity, such as proteomics analysis using nanoESI-MS.
authors.affiliation: Laboratoire de Chimie Organique et Macromoléculaire, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Le Gac
authors.affiliation: Laboratoire de Chimie Organique et Macromoléculaire, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex, France. Christian.Rolando@univ-lille1.fr.
authors.forename: Christian
authors.initials: C
authors.lastname: Rolando
authors.affiliation: Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), Cité Scientifique, Villeneuve d'Ascq Cedex, France.|UMR CNRS 8520, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex, France.
authors.forename: Steve
authors.initials: S
authors.lastname: Arscott