Time-Resolved Thickness and Shape-Change Quantification using a Dual-Band Nanoplasmonic Ruler with Sub-Nanometer...

Area of Science:

• Nanotechnology
• Biophysics
• Optical Sensing

Background:

• Time-resolved measurements of nanobiological objects are vital for understanding properties and performance.
• Optical sensing offers high throughput, sensitivity, and label-free operation but faces challenges in distinguishing layer changes from refractive index variations.
• Current methods often require complex modeling or multiparameter measurements.

Purpose of the Study:

• To develop a novel dual-band nanoplasmonic ruler for simultaneous, real-time measurement of thickness and refractive index variations.
• To enable label-free monitoring of nanobiological layer dynamics and nanostructure shape changes.
• To provide a generic nanofabrication approach for multimodal nanoplasmonic optical sensing.

Main Methods:

• Fabrication of mixed arrays of plasmonic nanoparticles with spectrally separated resonance peaks.
• Electrodynamic simulations and model experiments to validate the ruler's performance.
• Application to quantify lipid vesicle deformation and supported lipid bilayer formation.

Main Results:

• The dual-band nanoplasmonic ruler achieves simultaneous real-time measurements of thickness and refractive index with sub-nanometer resolution.
• Demonstrated ability to track nanostructure shape changes, including lipid vesicle deformation.
• Validated performance in analyzing uniform and heterogeneous layers.

Conclusions:

• The developed nanoplasmonic ruler offers a powerful tool for precise, label-free characterization of nanobiological systems.
• The nanofabrication approach is a versatile platform for multimodal optical sensing applications.
• Enables deeper insights into biomolecular layer dynamics and nanostructure transformations.