Hybrid Plasmonic Nanostructures for Enhanced Single-Molecule Detection Sensitivity.

Area of Science:

• Nanophotonics
• Biosensing
• Plasmonics

Background:

• Single-molecule detection requires high sensitivity, often hindered by background noise.
• Plasmonic nanoantennas confine and enhance light for improved detection.
• Existing antenna-in-box (AiB) platforms use gold, but hybrid materials offer potential improvements.

Purpose of the Study:

• To fabricate and characterize hybrid antenna-in-box (AiB) platforms using gold and aluminum.
• To computationally optimize AiB geometry and materials for enhanced performance.
• To evaluate the potential of hybrid AiBs for superior single-molecule detection sensitivity.

Main Methods:

• Computational optical property optimization of AiB structures.
• Fabrication of hybrid gold and aluminum AiB arrays using two-step electron beam lithography.
• Experimental validation of excitation and emission enhancements.

Main Results:

• Hybrid AiBs demonstrate improved signal-to-background ratios compared to gold-only structures.
• Computational models predicted and experimental results confirmed enhanced excitation and fluorescence.
• High reproducibility achieved in fabricating hybrid material AiB arrays.

Conclusions:

• Hybrid AiBs offer superior performance for single-molecule detection by improving signal-to-background and light enhancement.
• The developed fabrication process allows for reproducible creation of these advanced nanostructures.
• Hybrid AiB biosensors promise enhanced sensitivity for diverse applications, including multicolor fluorescence and vibrational spectroscopy.