Nanoscopic imaging of thick heterogeneous soft-matter structures in aqueous solution

Area of Science:

• Biophysics
• Materials Science
• Microscopy

Background:

• Imaging soft matter at the nanoscale is challenging due to thermal fluctuations causing motion blur.
• Optical heterogeneities in samples lead to geometric distortions in traditional microscopy.
• High-bandwidth, high-precision imaging is crucial for studying dynamic soft materials.

Purpose of the Study:

• To introduce a novel scanning probe technique for high-resolution imaging of soft, heterogeneous, and porous materials.
• To demonstrate precise localization and dynamics quantification of nanoscale structures in aqueous environments.
• To address and correct image distortions caused by optical properties of the sample.

Main Methods:

• Development and application of quantitative thermal noise imaging (QTNI), a 3D scanning probe technique.
• Imaging of individual microtubules and collagen fibrils in a network.
• Utilizing high-bandwidth detection to capture subnanometre amplitude dynamics.

Main Results:

• Achieved precise localization of structures with approximately 10 nm accuracy.
• Quantified local dynamics with 50 kHz bandwidth and subnanometre amplitudes.
• Successfully corrected image distortions arising from optically dense sample regions.

Conclusions:

• Quantitative thermal noise imaging provides a powerful new method for nanoscale imaging of soft matter.
• The technique enables precise localization and dynamic characterization of biological and porous materials.
• QTNI overcomes limitations of conventional microscopy for complex, heterogeneous samples in solution.