Polymethyl methacrylate (PMMA) was coated on the surface of carbon nanotubes by in-situ emulsion polymerization, and particle-free matrix assisted laser desorption/ionization mass spectrometry analysis was successfully carried out by applying this kind of soluble carbon nanotube as matrix. The polymer derivatized carbon nanotubes can dissolve in some solvents depending on their good hydrophilic surface. This novel matrix was applied to the mass spectrometry analysis of small organic molecules, standard peptide mixture, polymer and protein digests successfully. The immobilized carbon nanotube with PMMA is not only able to dissolve in the sample solution thoroughly, but also absorb and transfer the laser energy effectively. This novel matrix gained mass spectra with low noise background within a low mass range, good reproducibility of signals and wide mass range. This kind of carbon nanotube has potential application to the rapid analysis of small molecules and peptides for proteomics research.

Key words: carbon nanotube, mass spectrometry, matrix