Novel perspectives for the application of total internal reflection microscopy

Area of Science:

• Colloidal science
• Surface science
• Nanotechnology

Background:

• Total Internal Reflection Microscopy (TIRM) measures particle-wall interactions with high resolution.
• TIRM's accuracy depends on a priori knowledge of the intensity-distance relationship (I(z)).
• Existing constraints limit TIRM applications, especially on reflective surfaces.

Purpose of the Study:

• To develop a method for experimentally determining the I(z) relationship in TIRM.
• To overcome limitations of TIRM, enabling broader experimental conditions.
• To extend TIRM's applicability to challenging surfaces like gold.

Main Methods:

• Utilizing distance-dependent particle-wall hydrodynamic interactions.
• Experimentally calibrating the TIRM intensity-distance relationship (I(z)).
• Applying the method to measure interaction potentials without prior I(z) knowledge.

Main Results:

• Successfully determined the I(z) relationship experimentally.
• Demonstrated TIRM's extended applicability to various surfaces.
• Enabled TIRM measurements on highly reflecting gold surfaces.

Conclusions:

• The new method removes the need for a priori I(z) calibration in TIRM.
• Hydrodynamic interactions provide a robust way to calibrate TIRM experimentally.
• This advancement significantly broadens the scope and accessibility of TIRM measurements.