Beijing National Laboratory for Molecular Sciences, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Talanta. 2013 Sep 30;114:54-9. doi: 10.1016/j.talanta.2013.04.007. Epub 2013 Apr 12.
In this work, the signal intensity of ambient plasma assisted laser desorption ionization mass spectrometry (PALDI-MS) was significantly increased with graphene as matrix. The graphene functions as a substrate to trap analytes, absorb energy from the visible laser irradiation and transfer energy to the analytes to facilitate the laser desorption process. The desorbed analytes are further ionized by helium plasma and analyzed by MS. Compared with a traditional organic matrix, α-cyano-4-hydroxycinnamic acid (CHCA), graphene exhibited much higher desorption efficiency for most of the compounds benefitting from the strong optical absorption at 532nm. The performance has been confirmed by the facile analysis of more than forty compounds with various structures. Additionally, this method was successfully applied to distinguish three kinds of Chinese tea leaves by detecting the endogenous caffeine and theanine, which proved the utility, facility and convenience of this method for rapid screening of main components in real samples.
在这项工作中，通过使用石墨烯作为基质，环境等离子体辅助激光解吸电离质谱（PALDI-MS）的信号强度得到了显著增强。石墨烯作为一个基质，能够捕获分析物、吸收可见光激光辐射的能量并将能量传递给分析物，从而促进激光解吸过程。解吸的分析物进一步被氦等离子体电离，并通过 MS 进行分析。与传统的有机基质α-氰基-4-羟基肉桂酸（CHCA）相比，石墨烯对大多数化合物表现出更高的解吸效率，这得益于其在 532nm 处的强光学吸收。通过对四十多种具有不同结构的化合物的简便分析，证实了这种方法的有效性。此外，该方法还成功地应用于区分三种中国茶叶，通过检测内源性咖啡因和茶氨酸，证明了该方法在快速筛选实际样品中主要成分方面的实用性、简便性和便利性。
