Development of Liquid-Phase Plasmonic Sensor Platforms for Prospective Biomedical Applications

Area of Science:

• Nanotechnology
• Optical Sensing
• Biomedical Diagnostics

Background:

• Localized Surface Plasmon Resonance (LSPR) offers sensitive refractive index detection via light-metal electron interactions.
• LSPR sensors are advantageous for point-of-care applications due to their sensitivity, cost-effectiveness, and compact size.

Purpose of the Study:

• Develop a label-free Localized Surface Plasmon Resonance (LSPR)-based nanohole array (NHA) sensor platform.
• Enable real-time monitoring of probe/target binding events for low-level biomolecular detection.
• Establish a liquid-phase sensing setup for enhanced biomedical diagnostics.

Main Methods:

• Finite-difference time-domain simulations determined optimal 75 nm gold thickness for NHAs.
• Scanning electron microscopy was used for visual examination of fabricated NHA structures.
• A polydimethylsiloxane (PDMS) microfluidic channel was fabricated using 3D printing for liquid-phase measurements.

Main Results:

• Optimized gold nanohole array (NHA) structures were fabricated and characterized.
• A functional liquid-phase sensing setup was successfully integrated with the NHA sensor.
• Reflectance-mode measurements confirmed the sensor's functionality and reproducibility in a liquid environment.

Conclusions:

• The developed NHA-based LSPR sensor platform is effective for label-free, real-time biomolecular detection.
• The liquid-phase microfluidic integration enables sensitive biomolecular monitoring for diagnostics.
• This research validates a reproducible and functional LSPR sensing platform for biomedical applications.