title: Surface-assisted laser desorption ionization mass spectrometry techniques for application in forensics.
abstract: Matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) is an excellent analytical technique for the rapid and sensitive analysis of macromolecules (>700 Da), such as peptides, proteins, nucleic acids, and synthetic polymers. However, the detection of smaller organic molecules with masses below 700 Da using MALDI-MS is challenging due to the appearance of matrix adducts and matrix fragment peaks in the same spectral range. Recently, nanostructured substrates have been developed that facilitate matrix-free laser desorption ionization (LDI), contributing to an emerging analytical paradigm referred to as surface-assisted laser desorption ionization (SALDI) MS. Since SALDI enables the detection of small organic molecules, it is rapidly growing in popularity, including in the field of forensics. At the same time, SALDI also holds significant potential as a high throughput analytical tool in roadside, work place and athlete drug testing. In this review, we discuss recent advances in SALDI techniques such as desorption ionization on porous silicon (DIOS), nano-initiator mass spectrometry (NIMS) and nano assisted laser desorption ionization (NALDI™) and compare their strengths and weaknesses with particular focus on forensic applications. These include the detection of illicit drug molecules and their metabolites in biological matrices and small molecule detection from forensic samples including banknotes and fingerprints. Finally, the review highlights recent advances in mass spectrometry imaging (MSI) using SALDI techniques.
authors.affiliation: Mawson Institute, University of South Australia, Mawson Lakes, South Australia, 5095, Australia.
authors.forename: Taryn
authors.initials: T
authors.lastname: Guinan
authors.affiliation: School of Physical and Chemical Sciences, Flinders University, Bedford Park, South Australia, 5042, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Kirkbride
authors.affiliation: School of Physical and Chemical Sciences, Flinders University, Bedford Park, South Australia, 5042, Australia.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Pigou
authors.affiliation: Mawson Institute, University of South Australia, Mawson Lakes, South Australia, 5095, Australia.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ronci
authors.affiliation: School of Physical and Chemical Sciences, Flinders University, Bedford Park, South Australia, 5042, Australia.
authors.forename: Hilton
authors.initials: H
authors.lastname: Kobus
authors.affiliation: Mawson Institute, University of South Australia, Mawson Lakes, South Australia, 5095, Australia.
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry; D003878:Dermatoglyphics; D004867:Equipment Design; D005554:Forensic Medicine / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008670:Metals / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry; D012666:Semiconductors; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D015813:Substance Abuse Detection / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties
chemical_list: D008670:Metals; D010087:Oxides; D002244:Carbon
keywords: forensic analysis; illicit drugs; laser desorption ionization mass spectrometry; nanostructured surfaces