Applications of silver nanoparticles capped with different functional groups as the matrix and affinity probes in surface‐assisted laser desorption/ionization time‐of‐flight and atmospheric pressure matrix‐assisted laser desorption/ionization ion trap mass spectrometry for rapid analysis of sulfur drugs and biothiols in human urine

Abstract

A strategy is presented for the analysis of sulfur drugs and biothiols using silver nanoparticles (AgNPs) capped with different functional groups as the matrix and affinity probes in surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) and atmospheric pressure-matrix assisted laser desorption/ionization ion trap mass spectrometry (AP-MALDI-ITMS). Biothiols adsorbed on the surface of AgNPs through covalent bonding were subjected to ultraviolet (UV) radiation that enabled desorption and ionization due to the excellent photochemical property of NPs. The proposed method has been successfully applied for the determination of cysteine and homocysteine in human urine samples using an internal standard. The limit of detection (LOD) and limit of quantification (LOQ) for cysteine and homocysteine in urine sample are 7 and 22 nM, respectively, with a relative standard deviation (RSD) of <10%. The advantages of the present method compared with the methods reported in the literature for biothiol analysis are simplicity, rapidity and sensitivity without the need for time-consuming separation and tedious preconcentration processes. Additionally, we also found that the bare AgNPs can be directly used as the matrix in MALDI-TOF MS for the analysis of sulfur drugs without the addition of an extra proton source.

Is it possible to consider «kinetomics» and «argyromics» as novel trends of functional morphology and systems biology of parasitic and nonparasitic protozoa? a brief analytical review

“…In this case both Ag and other inorganic non-immunochemical agents for morphological staining can be used as MS labels for colocalization analysis. The above fact is consistent with the existing analytical procedures where Ag + labeling is applied for characterization of hydrogen-bonded supramolecular assemblies by MALDI-TOF mass spectrometry (Timmerman, 2000), as well as the silver nanoparticles (Shrivas, 2008), while for ESI MS detection Ag-staining is useful as a complementary method for Coomassie-staining (Winkler, 2007), and for the MS analysis combined with gel-electrophoresis combined radiolabelling and silver staining can be successfully applied for visualization, localization, and identification of proteins or peptides (Westrook, 2001). …”

Analysis of Biomolecules through Surface‐Assisted Laser, Desorption/Ionization Mass Spectrometry Employing Nanomaterials

“…34 The selective capture and determination of biothiols and sulfur drugs in urine was also demonstrated through SALDI MS and atmospheric pressure-MALDI ion trap MS with silver NPs capped with various functional groups. 56 63 Compared to dispersed Au NPs, the use of LBL films provided increased sensitivity (sub-femtomole) for angiotensin I and cytochrome C and a wider analyte mass range (up to 12 kDa). Because Pt is inert and has a high-melting temperature, high crystallinity and low thermal conductivity, highly stable Pt-based nanomaterials absorbing laser light were reported as useful matrices for SALDI MS analyses.…”

Silver Oxide Based Nanoparticle Assisted Laser Desorption/Ionization Mass Spectrometry for the Detection of Low Molecular Weight Compounds

“…Gold nanoparticles can be used to modify functional thiol compounds 8) or coat a silver layer 9) and, hence, can be used as a nity probes. e use of silver nanoparticles in conjunction with LDI 10,11) has been reported to result in the selective ionization of ole nic target molecules. 12) Silver ions can be coordinated to an ole n to form organometallic π-complexes through σ-type donation from the lled π-orbital of the carbon-carbon double bond with concomitant π-backbonding into the empty π-orbital.…”