Facile Synthesis of Gold@Graphitized Mesoporous Silica Nanocomposite and Its Surface-Assisted Laser Desorption/Ionization for Time-of-Flight Mass Spectroscopy

Abstract

In this work, a novel core-shell structured gold@graphitized mesoporous silica nanocomposite (Au@GMSN) was synthesized by in situ graphitization of template within the mesochannels of mesoporous silica shell on gold core and demonstrated to be promising nanomaterials for surface-assisted laser desorption/ionization time-of-flight mass spectroscopy (SALDI-TOF MS). The integration of the graphitized mesoporous silica with the gold nanoparticles endowed Au@GMSN with large surface areas of graphitic structure, good dispersibility, and strong ultraviolet (UV) absorption. Au@GMSN exerted the synergistic effect on the efficient detection of small-molecular-weight analytes including amino acids, neutral saccharides, peptides, and traditional Chinese medicine. The Au@GMSN-assisted laser desorption/ionization exhibited the following superiorities: high ionization efficiency, low fragmentation interference, favorable salt tolerance, and good reproducibility. Moreover, because of the large hydrophobic inner surface area of the graphitized mesoporous silica shell, the Au@GMSN demonstrated its promising capacity in the pre-enrichment of aromatic analytes prior to SALDI-TOF MS, which favored rapid and sensitive detection.

Silica-coated super-paramagnetic iron oxide nanoparticles (SPIONPs): a new type contrast agent of T1 magnetic resonance imaging (MRI)

“…Mice were observed for behavioral changes for fifteen days and then both mice were sacrificed. Moreover, the silica shell has been extensively studied for different biological applications owing to of its excellent biocompatibility, nontoxicity, stability and simply further conjugation with different functional groups 26,27 . The influence of reaction time on structure growth of the as-prepared SPIONPs is examined by TEM and HRTEM analysis.…”

Designer SiO2@Au nanoshells towards sensitive and selective detection of small molecules in laser desorption ionization mass spectrometry

“…Furthermore, the performance of SiO 2 @Au-2 nanoshells as alternative matrix for LDI MS analysis has been carefully studied in both the positive and negative ion mode ( Figure 4). Compared to the results from previous reports applying graphene oxide/multi-walled carbon nanotubes 33 and gold@graphitized mesoporous silica nanocomposite 38 as LDI substrates or other nano-assisted laser desorption ionization (NALDI) approaches 39 (sensitivity arranging from 50 fmol to 100 pmol), SiO 2 @Au materials were stable with little fragmentation during LDI process and provided comparable sensitivity (100 fmol-100 pmol) to small molecules in the MS detection.…”

MoS2/Ag nanohybrid: A novel matrix with synergistic effect for small molecule drugs analysis by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

“…To achieve sensitive and reproducible MALDI-TOF MS, great endeavors have been devoted to the combined functionalization of nanomaterials. [16][17][18][19] Shi et al prepared highly water-dispersible polydopamine-modified carbon nanotubes to overcome the poor dispersibility of pristine multi-walled carbon nanotubes (MWCNTs) and demonstrated that the composites have improved the performance of the analysis of various water soluble small molecules. [16] Apart from the increased dispersibility, some hybrid nanocomposites can exhibit synergistic effect in the enhancement of the LDI efficiency of analytes.…”

“…Xu et al developed a hybrid nanocomposite with a large graphitized inner surface area, strong UV adsorption and excellent dispersibility, which have improved the LDI efficiency and prevented inhomogeneous distribution. [17] Kim et al designed a graphene oxide/multi-walled carbon nanotube double layer and applied it as a MALDI substrate.…”

“…This often results in multiple alkali metal adducts in the mass spectrum, which is difficult to identify. [12,17] In contrast, the negative ion spectrum is much clearer and easier to interpret with one deprotonated ion peak present [20,21]. Furthermore, recent studies have showed that better sensitivity can be obtained in negative mode than positive mode for analytes.…”