Premium
Bare silica nanoparticles as concentrating and affinity probes for rapid analysis of aminothiols, lysozyme and peptide mixtures using atmospheric‐pressure matrix‐assisted laser desorption/ionization ion trap and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Author(s) -
Agrawal Kavita,
Wu HuiFen
Publication year - 2008
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3363
Subject(s) - chemistry , desorption , chromatography , matrix assisted laser desorption/ionization , adsorption , lysozyme , nanoparticle , mass spectrometry , aqueous solution , analytical chemistry (journal) , analyte , detection limit , matrix (chemical analysis) , ionization , ion , nanotechnology , organic chemistry , biochemistry , materials science
The analysis of peptide mixtures from urine and plasma samples using bare (uncapped) SiO 2 nanoparticles (NPs) with atmospheric‐pressure matrix‐assisted laser desorption/ionization mass spectrometry (AP‐MALDI‐MS) has been reported. The method was based on the adsorption of positively charged peptides on the surface of negatively charged SiO 2 NPs through the electrostatic force of attraction. The adsorption on the surface of SiO 2 NPs caused enhancement of ionization efficiency of analytes and subsequently increased the signal intensity of peptides. Maximum signal intensity was obtained at optimized concentration of SiO 2 NPs and pH of the aqueous solution. The limits of detection (LODs) obtained for different peptides in deionized water with and without using SiO 2 NPs were in the range 4.7–360 nM and 0.1–18.0 µM, respectively. The sensitivity of the proposed method was 21–53‐fold better than conventional use of AP‐MALDI‐MS. In addition, linearity in the range 9.5–95 nM was obtained for the peptide angiotensin‐II in deionized water with a correlation of estimation of 0.992 using an internal standard. The proposed method provided a simple way to facilitate the ionization of peptides, reduce sample complexity and increase the tolerance to salts and surfactants in the analysis of biological samples. The applicability of the present method was also demonstrated in the real‐world sample analysis of aminothiols and lysozyme using MALDI‐time‐of‐flight (TOF)‐MS. Copyright © 2008 John Wiley & Sons, Ltd.