Exploring natural products distribution in situ by using surface-assisted laser desorption/ionization imaging mass spectrometry

Matrix assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) is a technology used to provide high spatial resolution of molecules without labelling. MALDI IMS has frequently applied on microbial and plant samples and this application opens the door to exploration of the metabolic communication, and even the consequent discovery of new therapeutics (for human diseases) or biological control agents (for agricultural diseases) [1,2]. However, it is difficult to analyze small molecular natural products (< m/z 600) using MALDI IMS because of matrix signal interference. Over the past few years, surface-assisted laser desorption/ionization (SALDI) mass spectrometry has been developed as a solution for detecting small molecules [3]. Here, we reported the development of titanium oxide (TiO₂) as SALDI substrate for collecting mass signals of various natural products, such as amino acids, carbohydrates, lipopeptides, plant hormones, and so on. The TiO₂ nanowires were synthesized using a simple hydrothermal process [4] followed by chemical modification on the surface of TiO₂ nanowires. The results demonstrated that TiO₂ nanowires can be effectively used for imaging mass spectrometry applied to microbial and plant samples.

Acknowledgements: This work was supported by grants from the Ministry of Science and Technology, Taiwan, to Y.-L.Y. (MOST 104 – 2320-B-001 – 019-MY2).

Keywords: Imaging mass spectrometry, SALDI, TiO₂ nanowire.

References:

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