Interface-engineered plasmonic covalent organic framework nanofilms on TiO₂ nanotubes for universal mass spectrometry...

Area of Science:

• Materials Science
• Analytical Chemistry
• Biotechnology

Background:

• Covalent organic frameworks (COFs) show potential for mass spectrometry imaging (MSI).
• Integration of COFs with plasmonic nanostructures for MSI is underexplored.
• Existing MSI matrices face limitations in sensitivity and compatibility.

Purpose of the Study:

• To develop a novel plasmonic nanostructured platform using COFs for enhanced MSI.
• To investigate the synergistic effects of plasmonic enhancement, charge transfer, and ionization efficiency.
• To demonstrate the universal applicability of the platform across various biosample preparation techniques and biological systems.

Main Methods:

• Liquid-liquid interfacial self-assembly to create plasmonic gold nanoparticle-decorated COF nanofilms on titanium dioxide nanotubes.
• Fabrication of hierarchical nanostructured platforms.
• Application of the platform for matrix-free MSI using imprinting, stamping, and cryo-sectioning techniques.
• Analysis of whole-plant, fingerprint, and tissue samples.

Main Results:

• Achieved significant sensitivity improvement over conventional MSI matrices.
• Demonstrated universal compatibility with standard biosample preparation methods.
• Successfully mapped tissue-specific pollutant distribution and endogenous metabolites in Vigna unguiculata.
• Obtained 10-micrometer resolution lipid mapping in fingerprints and murine brains.
• Visualized ischemic stroke biomarkers in rat brains for pathogenesis studies.

Conclusions:

• Plasmonic COF nanofilms on titanium dioxide nanoarrays offer a powerful, universal matrix-free platform for MSI.
• The hierarchical design enhances MSI performance by combining plasmonic effects, charge transfer, and ionization efficiency.
• This approach bridges advanced materials science with life science applications, enabling detailed molecular imaging in complex biological systems.