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Tailoring Infrared Light-Molecule Coupling for Highly Sensitive Cortisol Detection Employing Aptamer-Conjugated Gold
Rong Chen1, Linlong Tang2, Guowei Li1
1Key Laboratory of Optoelectronic Technology and System, Ministry of Education of China, College of Optoelectronic Engineering Chongqing University, Chongqing 400044, P. R. China.
Analytical Chemistry
|December 6, 2024
Summary
Chemically synthesized gold nanonails enhance biosensing by improving the coupling between antennas and molecules. This novel approach enables highly sensitive, label-free detection of biomarkers like cortisol for disease diagnosis.
Area of Science:
- Nanotechnology
- Biosensing
- Spectroscopy
Background:
- Gold nanoantennas offer advantages for surface-enhanced infrared (SEIRA) biosensing due to cost-effectiveness and scalability.
- Current limitations include insufficient enhancement of biomolecular signals, hindering practical applications.
Purpose of the Study:
- To investigate the impact of antenna-molecule coupling on signal enhancement in SEIRA biosensing.
- To develop a novel gold nanostructure for improved biomarker detection.
Main Methods:
- Synthesized gold nanonails with sharp tips to amplify localized electric fields.
- Tuned nanonail aspect ratios to match molecular vibrational frequencies.
- Utilized aptamers and solution exchange for controlled antenna-molecule distance.
Main Results:
- Achieved a 3-order magnitude enhancement in biomarker detection levels by optimizing coupling efficiency.
- Demonstrated label-free, noninvasive detection of cortisol with a limit of 0.1 ng/mL.
- The developed method is significantly more sensitive than normal cortisol levels in human saliva.
Conclusions:
- Coupling rate is critical for enhancing molecular signals in SEIRA biosensing.
- Gold nanonails offer a viable strategy for sensitive biomarker detection.
- This approach has potential for disease diagnosis and health monitoring.
