Determination of Dopamine in Cerebrospinal Fluid by MALDI-TOF Mass Spectrometry with a Functionalized Graphene Oxide Matrix

Dopamine is a neurotransmitter, whose concentration change causes various nervous system disorders such as Parkinson's disease. In this study, hydroxyethyl methacrylate-functionalized graphene oxide was prepared and used as the substrate for matrix-assisted laser desorption/ionization (MALDI) for the mass spectrometric determination of dopamine. The results show that hydroxyethyl methacrylate-functionalized graphene oxide materials may be used as a matrix for MALDI. This approach combines enrichment and detection in a single step. The new method greatly shortens the analysis time and significantly reduces the amount of sample required for the analysis. The detection limit of the method was 20 ng/mL. These features not only ensure that the method is suitable for trace analysis, but also extend the range of application of MALDI analysis to biochemical science.