RESUMEN
Application of matrix-assisted laser desorption/ionization imaging mass spectrometry to microbiology and natural product research has opened the door to the exploration of microbial interactions and the consequent discovery of new natural products and their functions in the interactions. However, several drawbacks of matrix-assisted laser desorption/ionization imaging mass spectrometry have limited its application especially to complicated and uneven microbial samples. Here, we applied nanostructured silicon as a substrate for surface-assisted laser desorption/ionization mass spectrometry for microbial imaging mass spectrometry to explore fungal metabolic interactions. We chose Phellinus noxius and Aspergillus strains to evaluate the potential of microbial imaging mass spectrometry on nanostructured silicon because both fungi produce a dense mass of aerial mycelia, which is known to complicate the collection of high-quality imaging mass spectrometry data. Our simple and straightforward sample imprinting method and low background interference resulted in an efficient analysis of small metabolites from the complex microbial interaction samples.
Asunto(s)
Aspergillus/metabolismo , Basidiomycota/metabolismo , Silicio , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Nanoestructuras , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/instrumentación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Nanoscale silicon surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is an emerging matrix-free, highly sensitive MS analysis method. An important challenge in using nanoscale silicon SALDI-MS analysis is the aging and stability of silicon after storage in various environments. No proper nanoscale silicon SALDI-MS activation procedure has been reported to solve this issue. This study investigated the sensitivity, wettability, and surface oxidation behavior of nanoscale silicon surface SALDI-MS in a room, an inert gas atmosphere, and a vacuum environment. A simple vacuum oven desiccation was proposed to activate the SALDI-MS surface, and the limit of detection was further enhanced 1000 times to a 500 attomole level using this approach. The long-term stability and desorption/ionization mechanism were also investigated.