A monolithic microfluidic probe for ambient mass spectrometry imaging of biological tissues
Year: 2023
Type: article
Abstract: Ambient mass spectrometry imaging (MSI) is a powerful technique that allows for the simultaneous mapping of hundreds of molecules in biological samples under atmospheric conditions, requiring minimal sample preparation. We have developed nanospray desorption electrospray ionization (nano-DESI), a liquid extraction-based ambient ionization technique, which has proven to be sensitive and capable of achieving high spatial resolution. We have previously described an integrated microfluidic probe, which simplifies the nano-DESI setup, but is quite difficult to fabricate. Herein, we introduce a facile and scalable strategy for fabricating microfluidic devices for nano-DESI MSI applications. Our approach involves the use of selective laser-assisted etching (SLE) of fused silica to create a monolithic microfluidic probe (SLE-MFP). Unlike the traditional photolithography-based fabrication, SLE eliminates the need for the wafer bonding process and allows for automated, scalable fabrication of the probe. The chamfered design of the sampling port and ESI emitter significantly reduces the amount of polishing required to fine-tune the probe thereby streamlining and simplifying the fabrication process. We have also examined the performance of a V-shaped probe, in which only the sampling port is fabricated using SLE technology. The V-shaped design of the probe is easy to fabricate and provides an opportunity to independently optimize the size and shape of the electrospray emitter. We have evaluated the performance of SLE-MFP by imaging mouse tissue sections. Our results demonstrate that SLE technology enables the fabrication of robust monolithic microfluidic probes for MSI experiments. This development expands the capabilities of nano-DESI MSI and makes the technique more accessible to the broader scientific community.
Source: Lab on a Chip
DOI: 10.1039/d3lc00637a
Institutions: Purdue University West Lafayette, Leipzig University
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Awards: FOR 2177: Integrierte chemische Mikrolaboratorien (InCheM), Development of a high throughput system for molecular imaging of different cell types in mouse brain tissues, G3110643040, Novel Platform for Quantitative Subcellular Resolution Imaging of Human Tissues Using Mass Spectrometry, G5383212218, Pushing the Frontiers of Identification and Coverage in High-Resolution Spatially-Resolved Lipidomics
OpenAlex ID: W4387017206