김승현 (동국대학교 화학과)

김영관 (동국대학교 화학과)

김승현 (동국대학교 화학과)

김영관 (동국대학교 화학과)

MXene has been employed as a matrix in laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF-MS) for small molecules analysis, owing to its excellent laser absorption capacity, electrical conductivity, and photothermal conversion properties. However, despite these advantages, its application to LDI-TOF-MS has been impeded by the formation of many adducts with residual Li⁺ ions from synthetic processes. In this work, we functionalized the surface of MXene with phosphoric acid ligands having fluorinated structures to suppress Li⁺ adduct formation and promote softer ionization. Those ligands have strong affinity to the surface of MXene and thus facilitate the laser desorption/ionization process by leaching of Li⁺ ions through exchange reaction and lowering its surface energy. Surface functionalization of MXene was successfully confirmed with various analytical techniques. Compared to pristine MXene, the modified MXenes exhibited improved resolution, salt tolerance, detection limit, and reduced background noise in LDI-TOF-MS analysis of small molecules. Overall, this study demonstrated the importance of surface functionalization of MXene for small molecules analysis and suggests a new strategy to enhance its performance in LDI-TOF-MS.​