Visualizing vinca alkaloids in the petal of <i>Catharanthus roseus</i> using functionalized titanium oxide nanowire substrate for surface?assisted laser desorption/ionization imaging mass spectrometry

Imaging mass spectrometry (IMS) is a powerful technique that enables analysis of various molecular species at high spatial resolution with low detection limits. In contrast to the matrix-assisted laser desorption/ionization (MALDI-MS) approach, surface-assisted (SALDI) can be more effective in small molecules due absence interfering background signals m/z ranges. We developed functionalized TiO2 nanowire as solid substrate for IMS low-molecular-weight plant tissues. prepared nanowires using an inexpensive modified hydrothermal process and subsequently them chemically silane analogs overcome problem superhydrophilicity substrate. Chemical modification changed selectivity imprinting samples deposited on surface thus improved The was applied image distribution metabolites very fragile specimens such petal Catharanthus roseus. observed are distributed heterogeneously petal, which consistent previous results reported C. roseus leaf stem. intermediates corresponding biosynthesis pathway some vinca alkaloids were clearly shown petal. also performed profiling petals from five different cultivars plant. verified semi-quantitative capabilities imprinting/imaging approach by comparing LC-MS extracts. This suggested substrate-based SALDI complementary MALDI-MS.