Functionalized Graphene-Coated Cobalt Nanoparticles for Highly Efficient Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Analysis

Abstract

Graphene-coated cobalt nanoparticles surface-functionalized with benzylamine groups (CoC-NH(2) nanomagnets) were shown to effectively enrich analytes for surface-assisted laser desorption/ionization mass spectrometry (affinity SALDI-MS) analysis. These CoC-NH(2) nanomagnets are highly suited for use with affinity SALDI-MS because their mean diameter of 30 nm, high specific surface area of 15 m(2) g(-1), and high-strength saturation magnetization of 158 emu g(-1) led to efficient extraction of analytes by magnetic separation, which in turn enabled excellent SALDI-MS performance. Surface modification of CoC nanomagnets with benzylamine groups increased the yield of peptide ions and decreased fragmentation of benzylpyridinium ions, so-called "thermometer ions" formed through soft ionization. The CoC-NH(2) nanomagnets were used to extract perfluorooctanesulfonate from large volumes of aqueous solutions by magnetic separation, which was identified directly by SALDI-MS analysis with high sensitivity even at the sub-part-per-trillion level (∼0.1 ng/L). The applicability of CoC-NH(2) nanomagnets in conjunction with SALDI-MS for the enrichment and detection of pentachlorophenol, bisphenol A, and polyfluorinated compounds (PFCs) with varying chain length, which are environmentally significant compounds, as well as small drugs, was also evaluated.

Sensitive Detection of Aromatic Hydrophobic Compounds in Water and Perfluorooctane Sulfonate in Human Serum by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS) with Amine Functionalized Graphene-Coated Cobalt Nanoparticles

“…19) Brie y, CoC nanoparticles were prepared via ame spray pyrolysis, which proceeds by the combustion of a suitable metal containing an organic precursor. e surface of the CoC nanoparticles was functionalized with benzylamine groups (CoC-NH 2 ) according to previously reported procedures.…”

“…e surface of the CoC nanoparticles was functionalized with benzylamine groups (CoC-NH 2 ) according to previously reported procedures. 19) e CoC-NH 2 nanoparticles can be also commercially purchased as "TurboBeads Amine" (TurboBeads Co.).…”

“…19) More recently, it has been reported that humans and wildlife are globally exposed to poly uorinated compounds including PFOS, which is known to bioaccumulate in the human body at several tens of ppb in human serum. 25) erefore, application of the SALDI-MS technique for the detection of PFOS in human serum is bene cial and thus was performed in this study (Fig.…”

“…[13][14][15][16][17][18] Recently, we have demonstrated that amine functionalized graphene-coated cobalt nanoparticles (CoC-NH 2 nanoparticles) with an extremly thin (∼2 nm) layer of graphitic carbon (this points to the thin layer of graphitized carbon being interpreted as graphene), can be characterized by surface-assisted desorption/ionization mass spectrometry (SALDI-MS), and can be used as e ective extraction sorbents of poly uorinated compounds (PFCs) in water due to their high surface area and high-strength saturation magnetization. 19) Chlorophenol and polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants, and analytical methods are needed for their detection. 20,21) However, there are known problems with analysing these compounds by electrospray ionization mass spectrometry (ESI-MS) or by conventional matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis, due to di culties associated with protonation/deprotonation of the compounds.…”

Simultaneous and direct analysis of multiple types of organic contaminants in water based on a MOF decorated with a suitable quantity of Au nanoparticles, using SALDI-TOF MS

“…Various kinds of environmental organic and inorganic pollutants have been analyzed using SALDI-TOF MS including dioxin, 6 peruorinated chemicals (PFCs), [7][8][9][10] brominated ame retardants, [10][11][12] polycyclic aromatic hydrocarbons (PAHs), However, multi-residue methodology has not been successfully established and applied based on the SALDI-TOF MS technique. This could be very informative for the simultaneous measurement of the above mentioned pollutants to monitor the concurrences of organic contaminants in water samples.…”