Small molecule analysis using laser desorption/ionization mass spectrometry on nano-coated silicon with self-assembled monolayers


ANALYTICA CHIMICA ACTA, vol.729, pp.54-61, 2012 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 729
  • Publication Date: 2012
  • Doi Number: 10.1016/j.aca.2012.04.006
  • Title of Journal : ANALYTICA CHIMICA ACTA
  • Page Numbers: pp.54-61
  • Keywords: LDI, SAMs, Matrix-free target, Desorption/ionization, Small molecule analysis, Mass spectrometry, DESORPTION-IONIZATION, POROUS SILICON, PROTEIN, GOLD, ALKANETHIOLS, IMMUNOASSAY, SENSITIVITY, SUBSTRATE, FRICTION, SURFACES


Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is an emerging technique for the determination of the molecular weight of biomolecules and their non-covalent complexes without fragmentation. One problem with this technique is the use of excess amounts of matrices, which may produce intense fragment ions and/or clusters at low mass ranges between 1 and 800 Da. These fragments lead to interference, especially concerning the signals of small target molecules. Here, a simple, reusable, and quite inexpensive approach was demonstrated to improve the effectiveness of laser desorption/ionization mass spectrometry (LDI-MS) analysis, especially for small molecules, without using matrix molecules. In this study, substrates with controllable morphologies and thicknesses were developed based on the self-assembly of silane molecules on silicon surfaces using N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA) and octadecyltrichlorosilane (OTS) molecules. Prepared substrates with nano-overlayers were successfully used in the analysis of different types of small target molecules, namely acrivastine, L-histidine, L-valine, L-phenylalanine, L-arginine, L-methionine and angiotensin I. Our substrates exhibited clear peaks almost without fragmentation for all target molecules, suggesting that these surfaces provide a number of important advantages for LDI-MS analysis, such as ease of preparation, costs, reusability, robustness, easy handling and preventing fragmentation. (C) 2012 Elsevier B.V. All rights reserved.