Surface-assisted laser desorption/ionization mass spectrometry

Abstract

Laser desorption/ionization mass spectrometry (MS) is rapidly growing in popularity as an analytical characterization method in several fields. The technique shot to prominence using matrix-assisted desorption/ionization for large biomolecules (>700 Da), such as proteins, peptides and nucleic acids. However, because the matrix, which consists of small organic molecules, is also ionized, the technique is of limited use in the low-molecular-mass range (<700 Da). Recent advances in surface science have facilitated the development of matrix-free laser desorption/ionization MS approaches, which are referred to here as surface-assisted laser desorption/ionization (SALDI) MS. In contrast to traditional matrix-assisted techniques, the materials used for SALDI-MS are not ionized, which expands the usefulness of this technique to small-molecule analyses. This review discusses the current status of SALDI-MS as a standard analytical technique, with an emphasis on potential applications in proteomics.

Direct Mass Spectrometry-Based Approaches in Metabolomics

“…A variety of surface properties have been studied for matrix-free ionization of small molecules, for example: diamond nanowires [17] sol-gel derived silver-nanoparticles-impregnated thin biofilm [18], nanoporous gallium nitride-silver nanoparticles [19], metal oxide surfaces [20], nanofilament silicon [21], etc. Comprehensive reviews of innovative technologies using energy-absorbing materials for matrix-free LDI-MS have been recently published [22][23][24].…”

Separation of fingerprint constituents using magnetic silica nanoparticles and direct on-particle SALDI-TOF-mass spectrometry

“…Following evaporation, the material on the plate is subjected to analysis by laser desorption/ionisation (LDI) TOF-MS. This alternative method has been termed surface assisted-LDI-TOF-MS (SALDI-TOF-MS) [28][29][30][31]. SALDI-TOF-MS offers several advantages over organic matrices, such as ease of sample preparation, reduced background noise and high salt-tolerance [32].…”

Molecular histology analysis by matrix‐assisted laser desorption/ionization imaging mass spectrometry using gold nanoparticles as matrix

“…However, chemical interference arising from organic matrix cluster/adduct ions can mask the low‐mass region (<1000 Da) thus making the detection of small molecules difficult . The use of an inorganic matrix has been reported to prevent the matrix interference . Metal‐based nanoparticles (NPs) including those of Au, Ag, Pt, Zn and Ti have been applied as effective matrix and enabled the MALDI‐MS detection of small molecules and metabolites .…”

“…[6] The use of an inorganic matrix has been reported to prevent the matrix interference. [7,8] Metal-based nanoparticles (NPs) including those of Au, Ag, Pt, Zn and Ti have been applied as effective matrix and enabled the MALDI-MS detection of small molecules and metabolites. [9,10] Chemical functionalization (i.e., introduction of chemical group(s)) on the surface of these NPs are required to enhance their dispersion properties in aqueous solution, thus enabling the homogenous coating of these NPs on biological tissues by aero-spray.…”