Hardware and software solutions for implementing nanospray desorption electrospray ionization (nano‐DESI) sources on commercial mass spectrometers

Abstract

Nanospray desorption electrospray ionization (nano‐DESI) is an ambient ionization mass spectrometry imaging (MSI) approach that enables spatial mapping of biological and environmental samples with high spatial resolution and throughput. Because nano‐DESI has not yet been commercialized, researchers develop their own sources and interface them with different commercial mass spectrometers. Previously, several protocols focusing on the fabrication of nano‐DESI probes have been reported. In this tutorial, we discuss different hardware requirements for coupling the nano‐DESI source to commercial mass spectrometers, such as the safety interlock, inlet extension, and contact closure. In addition, we describe the structure of our custom software for controlling the nano‐DESI MSI platform and provide detailed instructions for its usage. With this tutorial, interested researchers should be able to implement nano‐DESI experiments in their labs.

Direct Three-Dimensional Mass Spectrometry Imaging with Laser Ablation Remote Atmospheric Pressure Photoionization/Chemical Ionization

“…16 Controlling the distance between the nano-DESI probe and the sample surface is critical to achieving high resolution but is also technically challenging to maintain, especially for thinner tissue sections. 17 be insufficient for some types of analysis, particularly when analyzing complex biological matrices. A common issue with nano-DESI is the stability of solvent flow, which is dependent on the inlet vacuum of the mass spectrometer.…”

“…However, the introduction of nano-DESI allowed for achieving resolution up to 6 μm . Controlling the distance between the nano-DESI probe and the sample surface is critical to achieving high resolution but is also technically challenging to maintain, especially for thinner tissue sections . Despite significant improvements, the ionization efficiency in nano-DESI may still be insufficient for some types of analysis, particularly when analyzing complex biological matrices.…”