Plasmonic Composites Aid Semi-quantitative Analysis and Identification of Low-molecular-weight Metabolites by Mass Spectrometry

DMSN@Ag/Au composites, with DMSN(dendritic mesoporous silica nanosphere), as the support and Au/Ag nanoparticles homogeneously loading on the surface, were employed as MALDI(matrix-assisted laser desorption/ionization) matrices. These composites enable highly sensitive MALDI metabolic analysis with a detection limit of 0.005 mg/mL. Moreover, these composites demonstrated good reproducibility in detection and provided an intrinsic Au+ signal as a reference to enhance the accuracy of quantitative analysis. Additionally, DMSN@Ag/Au facilitated Ag+ addition to the analyte and assisted in metabolite identification process. The composites are expected to serve as a new generation of multifunctional MALDI matrix and provide new ideas for clinical mass spectrometry analysis.