Atomic force microscope controlled topographical imaging and proximal probe thermal desorption/ionization mass...

Area of Science:

• Analytical Chemistry
• Surface Science
• Microscopy

Background:

• Correlating surface topography with chemical composition is crucial for material and biological analysis.
• Existing techniques often require sample manipulation or separate analyses, limiting direct comparison.
• Advancements in probe technology and mass spectrometry enable integrated imaging approaches.

Purpose of the Study:

• To develop and demonstrate a hybrid atmospheric pressure atomic force microscopy/mass spectrometry imaging system.
• To enable simultaneous acquisition of topographic and chemical information from the same sample area.
• To showcase the system's capability in analyzing diverse samples, including patterned surfaces and biological specimens.

Main Methods:

• Utilized nanothermal analysis probes for thermal desorption surface sampling.
• Integrated atmospheric pressure chemical ionization with mass analysis.
• Developed a hybrid system combining atomic force microscopy (AFM) and mass spectrometry (MS) imaging.
• Demonstrated co-registered imaging without sample transfer.

Main Results:

• Successfully obtained correlated AFM topographical and MS chemical images from inked patterns and a bacterial colony.
• Achieved high spatial resolution for AFM topography (0.2 μm × 0.8 μm).
• MS image resolution was limited to 2.5 μm × 2.0 μm due to data acquisition rates and detection limits.

Conclusions:

• The hybrid AFM/MS system effectively integrates topographic and chemical imaging capabilities.
• The system allows for direct correlation of surface morphology with chemical information.
• Further optimization of MS acquisition speed and detection sensitivity is needed to improve chemical imaging resolution.