title: Improved MALDI imaging MS analysis of phospholipids using graphene oxide as new matrix.
abstract: Matrix assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is an increasingly important technique for detection and spatial localization of phospholipids on tissue. Due to the high abundance and being easy-to-ionize of phosphatidylcholine (PC), therefore, selecting matrix to yield signals of other lipids has become the most crucial factor for a successful MALDI-IMS analysis of phospholipids. Herein, graphene oxide (GO) was proposed as a new matrix to selectively enhance the detection of other types of phospholipids that are frequently suppressed by the presence of PC in positive mode. Compared to the commonly used matrix DHB, GO matrix significantly improved signal-to-noise ratios of phospholipids as a result of its high desorption/ionization efficiency for nonpolar compounds. Also, GO afforded homogeneous crystallizations with analytes due to its monolayer structure and good dispersion, resulting in better reproducibility of shot-to-shot (CV < 13%) and spot-to-spot (CV < 14%) analysis. Finally, GO matrix was successfully applied to simultaneous imaging of PC, PE, PS and glycosphingolipid in the mouse brain, with a total of 65 phospholipids identified.
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Xinwen
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, P. R. China.|Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, P. R. China.|Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China.|Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Haojie
authors.initials: H
authors.lastname: Lu