Electrospun Nanofiber Mats as “Smart Surfaces” for Desorption Electrospray Ionization Mass Spectrometry (DESI MS)-Based Analysis and Imprint Imaging

Abstract

In this paper, desorption electrospray ionization mass spectrometry (DESI MS)-based molecular analysis and imprint imaging using electrospun nylon-6 nanofiber mats are demonstrated for various analytical contexts. Uniform mats of varying thicknesses composed of ∼200 nm diameter fibers were prepared using needleless electrospinning. Analytical applications requiring rapid understanding of the analytes in single drops, dyes, inks, and/or plant extracts incorporated directly into the nanofibers are discussed with illustrations. The possibility to imprint patterns made of printing inks, plant parts (such as petals, leaves, and slices of rhizomes), and fungal growth on fruits with their faithful reproductions on the nanofiber mats is illustrated with suitable examples. Metabolites were identified by tandem mass spectrometry data available in the literature and in databases. The results highlight the significance of electrospun nanofiber mats as smart surfaces to capture diverse classes of compounds for rapid detection or to imprint imaging under ambient conditions. Large surface area, appropriate chemical functionalities exposed, and easiness of desorption due to weaker interactions of the analyte species are the specific advantages of nanofibers for this application.

Mass spectrometry imaging for direct visualization of components in plants tissues

“…Imprinting [62] has been applied in recent years, mainly used for inorganic matrix deposition. Its principle is that placing tissue slice on the surface of the nanomaterial, covered by porous Teflon, TLC plate [63,64], or other nanomaterials [65,66] with certain pressure. Compounds on the sample surface would be transferred to the nanomaterial, then analyzed directly on the nanomaterial plate after removing the sample slice.…”

Review and perspectives on the applications of mass spectrometry imaging under ambient conditions

“…“Smart surfaces” composed of electrospun nylon‐6 nanofiber mats were developed as DESI‐MS imprinting surfaces to capture a wide range of compounds for enhanced imaging. Imprint images of plant tissues such as petals, leaves, and slices of rhizomes, and fungal growth on fruit were reproduced using these novel smart surfaces …”

Advancements in Non-Invasive Biological Surface Sampling and Emerging Applications

“…Therefore, involvement of suitable sample preparation methods for surface imaging using direct-to-MS approaches are becoming more and more crucial. With this intention, Hemalatha et al imprinted patterns of printing inks, plant parts, and fungal growth on electrospun nanofiber mats and employed desorption electrospray ionization mass spectrometry (DESI-MS) to rapidly analyze and capture images of the imprinted patterns and analyte droplets [91]. Nanofiber mats were electrospun from a solution of Nylon-6 dissolved in formic acid and characterized by SEM.…”