Analysis of Biomolecules through Surface‐Assisted Laser, Desorption/Ionization Mass Spectrometry Employing Nanomaterials

Abstract

Nanomaterials, primarily nanoparticles (NPs), can serve as an alternative matrix for the analysis of various biomolecules through surface-assisted laser desorption/ionization mass spectrometry (SALDI MS). SALDI MS has been developed to overcome poor reproducibility and high background in the lowmass region commonly occurring in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Various nanomaterials, unmodified or functionalized with recognition ligands, can have a strong affinity toward certain analytes and thus are applicable for their concentration and enrichment from complex biological matrices. In mass spectrometry imaging (MSI), the use of NPs instead of the conventional matrices can improve the spatial resolution up to the cellular level. In this review, the nature of NPs, the methods of sample preparation and approaches for quantitation of biomolecules through SALDI MS are discussed. Practical applications and limitations of SALDI MS employing NPs for separate samples and MSI are mentioned. With regard to the nature of MSI analysis, the use of nanostructured surfaces for MSI is also reflected in this review.

Clusters of Monoisotopic Elements for Calibration in (TOF) Mass Spectrometry

“…Gold clusters provide simple and fast determination of accurate mass compared with common calibration standards, such as peptides or proteins. Moreover, AuNPs can enhance ionization in various techniques, such as surface-assisted laser desorption ionization (SALDI), nanoparticle-assisted laser desorption ionization (NALDI), and gold nanoparticle-assisted laser desorption ionization (GALDI) [20][21][22]. The structure and properties of gold and phosphorus clusters are well known [23][24][25][26].…”

Membrane-based detection of lead ions in seawater, urine and drinking straws through laser desorption/ionization

“…Under pulsed laser irradiation (Nd:YAG, 355 nm), we have found that Pb 2+ ions desorb from the porous MCEM to produce [Pb] + peaks in the resulting mass spectra. Relative to the noisy spectra typically obtained when using organic matrixand NP-assisted LDI approaches [21][22][23][24][25][26][27][28][29], employing the MCEM as an LDI matrix provides clean mass spectra. When using an MCEM, first to concentrate Pb 2+ ions and then as an efficient LDI substrate, our membrane-based surface-enhanced laser desorption/ionization (SELDI) approach exhibited high sensitivity [limit of detection (LOD): 0.05 nM] and selectivity (tolerance at least 1000-fold relative to other metal ions) for the detection of Pb 2+ ions.…”

“…Moreover, the choice of matrix is usually based on an empirical approach; therefore, matrix selection and optimization of the sample preparation procedure are major issues affecting the success of the MALDI-MS technique. As a result, many organic-matrix-free approaches to LDI-MSusing high-molecular-weight organic matrices, sol-gel materials, or silicon or metal substrates -have been developed for analyses of low-molecular-weight compounds [22,[27][28][29]. Recently, nanomaterial (NM)-based surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) has become an attractive technique for the analysis of small analytes [30][31][32][33][34][35].…”

Small‐ and large‐sized iron(II, III) oxide nanoparticles for surface‐assisted laser desorption/ionization mass spectrometry of small biomolecules

“…Recent developments in SALDI-MS technique involve the design of surfaces/substrates for efficient detection of organic and inorganic compounds for applications including, but not limited to pharmaceutical, 14 proteomics (peptides and proteins), 15 biological, 16 and forensics. 17 Materials such as silicon-based ( e.g ., desorption/ionization on silicon; DIOS), 18–20 organic-based ( e.g ., immobilized carbon nanotubes, 21 activated carbon surface, 22 oxidized graphitized carbon black, 23 ) metal-based/metal-oxide ( e.g ., Au, 24 Pd, 25 Pt, 26–27 HgSe, 28 titania nanotube arrays, 29 TiO 2 , 30–31 MgO, 32 lithium-rich composite metal oxide 33 ), metal-organic frameworks, 34–36 quantum dots, 37 and multilayer-coated ( e.g ., two-layered amorphous silicon 38 , MoS 2 /TiO 2 /SiNW surface 39 ) have been utilized as surfaces for SALDI with advantages including high absorption coefficient for laser energy and low matrix interferences.…”