Electrospun Nanofibers as Substrates for Surface-Assisted Laser Desorption/Ionization and Matrix-Enhanced Surface-Assisted Laser Desorption/Ionization Mass Spectrometry

Abstract

Electrospun polymeric nanofibers (polyacrylonitrile, poly(vinyl alcohol), and SU-8 photoresist) and carbon nanofibers pyrolyzed to final temperatures of 600, 800, and 900 °C were used as substrates for surface-assisted laser desorption/ionization (SALDI) and matrix-enhanced surface-assisted laser desorption/ionization (ME-SALDI) analyses. Sample preparation of polymeric analytes using the electrospun target plate for SALDI analysis is simple and fast. Signal enhancements for poly(ethylene glycol) were noted with nanofibrous carbon substrates compared to those obtained with commercially available stainless steel plates when no organic matrix is used. Minimal fragmentation was observed. Poly(ethylene glycol) with a molecular weight as high as 900 000 Da was successfully detected using the carbon nanofibrous substrate processed to 800 °C, which is the highest molecular weight that has been studied by SALDI. Small molecules were detected using nanofibrous carbon substrate processed to 800 °C. For example, spectra of glucose, arginine, and crystal violet were obtained with no observed interferences in the low molecular weight range. The SALDI results show enhanced shot-to-shot reproducibility compared to matrix-assisted laser desorption/ionization (MALDI). High-quality polystyrene spectra were obtained for the first time using SALDI nanofibrous polyacrylonitrile substrates. Significantly enhanced signal-to-noise ratios were obtained using ME-SALDI compared to conventional MALDI or SALDI for the studied analytes. A detection limit of 400 amol was achieved for angiotensin I using the nanofibrous carbon ME-SALDI substrate.

Analyses of functional polymer-modified nanoparticles for protein sensing by surface-assisted laser desorption/ionization mass spectrometry coupled with HgTe nanomatrices

“…Although we could detect PEG species at all molecular weights in this range, the peak intensity of PEG 42,700 was quite low, because the ionization and desorption efficiencies of ions of relatively high molecular weight are typically low [62][63][64][65]. To the best of our knowledge, this PEG species has the highest molecular weight ever analyzed using an LDI-MS method [66].…”

Recent advances in the preparation of adsorbent layers for thin‐layer chromatography combined with matrix‐assisted laser desorption/ionization mass‐spectrometric detection

“…Some reviews coved application of SALDI MS technique in analysis of different classes of organic compounds . SALDI MS being performed with UTLC plates with bonded matrix sounds even more promising . Plates with nanofibrous carbon substrates and composite nanofibers (PAN/Nafion®/CNT) demonstrated minimal fragmentation and signal enhancements for poly(ethylene glycol) compared to those obtained with commercially available stainless steel plates.…”

“…A set of six laser dyes, as well as a mixture of three labeled amino acids: lysine, threonine, and phenylalanine, were fully resolved on the carbon UTLC plate demonstrating tunable retention and plate number values above 10 000 theoretical plates. Later, other polymeric nanofibers (polyacrylonitrile, poly(vinyl alcohol) and carbon nanofibers ) were pyrolyzed to final glassy carbon ultra‐thin layers demonstrating ability for surface‐assisted laser desorption/ionization and matrix‐enhanced surface‐assisted laser desorption/ionization analyses which are discussed in Section 3.2.…”

Nanomaterials as Assisted Matrix of Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for the Analysis of Small Molecules

“…Due to the inherent advantages, such as unique structure, large surface area, good performance in optical properties, carbon-based nanomaterials including fullerenes [28], nanodiamond [29,30], nanofibers [31], nanohorns, nanotubes, nanodots, and graphene have been considered as a kind of good candidate matrix for LDI to analysis of small molecules since Sunner and co-workers [19] demonstrated that graphite particles with size of 2–150 µm can be served as matrix for LDI-TOF MS.…”