Surface-assisted laser desorption/ionization
From Wikipedia, the free encyclopedia
Surface-assisted laser desorption/ionization (SALDI) is a soft laser desorption technique used for mass spectrometry analysis of biomolecules, polymers, and small organic molecules.[1][2][3][4] In its first embodiment Koichi Tanaka used a cobalt/glycerol liquid matrix[1] and subsequent applications included a graphite/glycerol liquid matrix as well as a solid surface of porous silicon.[3] The porous silicon represents the first matrix-free SALDI surface analysis allowing for facile detection of intact molecular ions,[3][5] these porous silicon surfaces also facilitated the analysis of small molecules at the yoctomole level.[5][6] At present laser desorption/ionization methods using other inorganic matrices such as nanomaterials are often regarded as SALDI variants. As an example, silicon nanowires[7] as well as Titania nanotube arrays (NTA) have been used as substrates to detect small molecules.[8] SALDI is used to detect proteins and protein-protein complexes.[9] A related method named "ambient SALDI" - which is a combination of conventional SALDI with ambient mass spectrometry incorporating the direct analysis real time (DART) ion source has also been demonstrated.[10] SALDI is considered one of the most important techniques in MS and has many applications.[11]