The supply capillary delivers a small amount of solvent to the sample surface to form a thin liquid film that desorbs surface molecules; the adjacent collection capillary draws the film in and applies a high voltage to generate an electrospray, completing ionization before the ions enter the mass analyzer. The capillary spacing and film volume determine the micro-region sampling size.
Compared with single-capillary DESI's remote spray, Nano-DESI's liquid film is more controlled and stays closer to the surface, which improves sampling reliability and reproducibility and makes it well suited to fine micro-region analysis.
By precisely controlling the film position and moving the sample point by point, Nano-DESI can perform micro-region sampling of tissue surfaces and reconstruct molecular distributions. Its sampling area is smaller than that of conventional DESI spray spots, giving finer spatial resolution, typically down to tens of microns.
For ambient imaging requiring more stable and finer results than DESI, Nano-DESI is the high-precision variant in the DESI family; but its film contact also means it is more sensitive to surface flatness and humidity.
Nano-DESI images mid-to-high polarity molecules (lipids, metabolites, peptides) well; its ambient, matrix-free nature (no reliance on a MALDI matrix) benefits small-molecule analysis. It suits fine sampling of tissue micro-regions and cell clusters.
For subcellular needs it remains insufficient compared with TOF-SIMS/t-MALDI; for ambient, micro-region, low-preparation needs, it is the high-precision choice within the DESI system.
Nano-DESI, LDPI, and DPI all belong to the ambient, matrix-free family but differ in ionization mechanism: Nano-DESI relies on liquid-phase electrospray, whereas LDPI/DPI rely on photochemical/dual-photoionization. Nano-DESI is a natural fit for molecules that ionize readily in the liquid phase; for matrix-free, high-sensitivity needs, compare it with DPI.
Selection should consider analyte polarity, micro-region precision, and the host instrument's ambient interface. Neo-Source LDPI/DPI can also serve as an alternative or supplement for ambient, matrix-free imaging.
To obtain detailed specifications, compatible models, or a quotation for the MSI LDPI / DPI full series imaging ion sources, visit the Neo-Source official website, or contact the official team for compatibility advice tailored to your mass spectrometer (Agilent / SCIEX / Thermo and other mainstream MS).