One-step synthesis of N, B-codoped carbon nanofiber as a novel matrix for high-throughput and efficient laser desorption/ionization mass spectrometry analysis

Abstract

It is of significance to analyze various small molecules with high efficiency using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this work, we synthesized N and B dual-doped 3D carbon (N, B-C) nanofiber as a promising MALDI matrix through a facile impregnation and thermal pyrolysis process. Compared to the control C nanofiber, the N and B codoping could enhance surface area, functional groups, defective and active sites, which was conducive to adsorb the laser and enrich the desorption/ionization of analytes. For the first time, the N, B-C nanofiber was utilized as a novel matrix for MALDI-TOF MS analysis of various small molecules both in the positive-ion and negative-ion modes. This matrix showed high signal to noise (S/N) ratio, excellent salt-tolerance, and homogeneous ion distribution for the analysis of amino acids, saccharides, polymers and surfactant, which was obviously superior to the traditional α-cyano-4-hydroxycinnamic acid (CHCA) and the control C nanofiber matrix. Noticeably, the wide linear ranges (0.05–5 mM) of glucose was achieved by MALDI-TOF MS with N, B-C nanofiber matrix. Meanwhile, the MALDI-TOF MS imaging could observe the change of different content glucose based on the ion peak of [M + Na]+. Furthermore, N, B-C nanofiber-assisted LDI-TOF MS has also been applied to identify and analyze the saccharides in the natural honey.