title: Molecular ionization from carbon nanotube paper.
abstract: Ambient ionization is achieved by spraying from a carbon nanotube (CNT)-impregnated paper surface under the influence of small voltages (≥3 V). Organic molecules give simple high-quality mass spectra without fragmentation in the positive or negative ion modes. Conventional field ionization is ruled out, and it appears that field emission of microdroplets occurs. Microscopic examination of the CNT paper confirms that the nanoscale features at the paper surface are responsible for the high electric fields. Raman spectra imply substantial current flows in the nanotubes. The performance of this analytical method was demonstrated for a range of volatile and nonvolatile compounds and a variety of matrices.
authors.affiliation: DST Unit of Nanoscience (DST UNS) and Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai-60036 (India).
authors.forename: Rahul
authors.initials: R
authors.lastname: Narayanan
authors.forename: Depanjan
authors.initials: D
authors.lastname: Sarkar
authors.forename: R Graham
authors.initials: RG
authors.lastname: Cooks
authors.forename: Thalappil
authors.initials: T
authors.lastname: Pradeep
keywords: Raman spectroscopy; ambient ionization; carbon nanotubes; field emission; paper spray ionization