Electrochemically synthesized nanoparticles (NPs) consisting of a gold core and a quaternary ammonium ("quat") shell were investigated as non-conventional matrix for the detection of low molecular weight analytes by Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry (MALDI-ToF-MS). The performance level of pristine NPs in promoting the analyte desorption/ionization processes was affected by the surfactant excess, due to shadowing of gold. Additional electrochemical protocols were developed for the controlled deposition of NPs on MALDI plates, aiming to improve the surface availability of nanostructured gold. Before use in mass spectrometry, the active area was treated by a potentiostatic procedure, that was proven to remove the excess of quat from the NPs surface. MALDI-MS and X-ray Photoelectron Spectroscopy showed that electrodeposited NPs can proficiently interact with small analytes, like cysteine and 4-fluoro-phenylalanine.
Core-shell gold nanoparticles as non-conventional matrix for MALDI-ToF-MS detection of amino acids: a preliminary study
CIOFFI, NICOLA;VAN DER WERF, INEZ DOROTHE';CALVANO, COSIMA DAMIANA;PALMISANO, Francesco;
2008-01-01
Abstract
Electrochemically synthesized nanoparticles (NPs) consisting of a gold core and a quaternary ammonium ("quat") shell were investigated as non-conventional matrix for the detection of low molecular weight analytes by Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry (MALDI-ToF-MS). The performance level of pristine NPs in promoting the analyte desorption/ionization processes was affected by the surfactant excess, due to shadowing of gold. Additional electrochemical protocols were developed for the controlled deposition of NPs on MALDI plates, aiming to improve the surface availability of nanostructured gold. Before use in mass spectrometry, the active area was treated by a potentiostatic procedure, that was proven to remove the excess of quat from the NPs surface. MALDI-MS and X-ray Photoelectron Spectroscopy showed that electrodeposited NPs can proficiently interact with small analytes, like cysteine and 4-fluoro-phenylalanine.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
