title: Laser desorption/ionization mass spectrometric assay for phospholipase activity based on graphene oxide/carbon nanotube double-layer films.
abstract: A new method for quantitative phospholipase activity assays using mass spectrometry (MS) and a supported thin film consisting of a graphene oxide (GO)/carbon nanotube (CNT) double layer as a substrate for laser desorption ionization (LDI) has been developed. Phospholipids were very efficiently analyzed by LDI-time-of-flight (TOF) MS on the GO/CNT films, presumably because of the affinity of phospholipids for the GO/CNT surface. Therefore, the rate of lipid hydrolysis was conveniently measured using LDI-TOF mass spectra obtained from a GO/CNT surface on which the phospholipid hydrolysis reaction mixtures had been spotted by comparing the mass-peak intensities of reactants and products. The present platform for phospholipase assays based on MS and GO/CNT double-layer films enables quantitative measurements at low cost, allows assays to be performed in a short time, and is compatible with an array format, unlike conventional assay methods.
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Jieon
authors.initials: J
authors.lastname: Lee
authors.forename: Young-Kwan
authors.initials: YK
authors.lastname: Kim
authors.forename: Dal-Hee
authors.initials: DH
authors.lastname: Min
mesh_terms: D006108:Graphite / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon; D010087:Oxides / Q000737:chemistry; D010740:Phospholipases / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D037742:Nanotubes, Carbon; D010087:Oxides; D006108:Graphite; D010740:Phospholipases