title: Dispersive liquid-liquid microextraction using functionalized Mg(OH)2 NPs with oleic acid as hydrophobic affinity probes for the analysis of hydrophobic proteins in bacteria by MALDI MS.
abstract: We report a dispersive liquid-liquid microextraction (LLME) method using surface modified Mg(OH)(2) nanoparticles (NPs) with oleic acid (OA) as hydrophobic affinity probes for the extraction and preconcentration of hydrophobic biomolecules prior to MALDI MS analysis. OA-capped Mg(OH)(2) NPs were characterized by FT-IR, SEM and TEM. The functionalized Mg(OH)(2) NPs are well dispersed in toluene with an average diameter of <35 nm. Under the optimum conditions, the method showed good linearity in the ranges of 10-400 nM and 0. 1-2.0 μM for valinomycin and gramicidin D, respectively. The limits of detection were in the region of 2.0 nM and 24 nM for valinomycin and gramicidin D, respectively. Moreover, the OA-capped Mg(OH)(2) NPs-assisted LLME method was successfully used for the rapid extraction/preconcentration of hydrophobic proteins in bacteria (Escherichia coli and Bacillus subtilis) prior to their identification by MALDI MS.
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan.
authors.forename: Suresh Kumar
authors.initials: SK
authors.lastname: Kailasa
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Wu
mesh_terms: D000345:Affinity Labels / Q000737:chemistry*; D001419:Bacteria / Q000378:metabolism; D001426:Bacterial Proteins / Q000032:analysis* / Q000302:isolation & purification; D057927:Hydrophobic and Hydrophilic Interactions; D059627:Liquid Phase Microextraction; D008276:Magnesium Hydroxide / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000345:Affinity Labels; D001426:Bacterial Proteins; D019301:Oleic Acid; D008276:Magnesium Hydroxide