Label-free detection of DNA hybridization with a compact LSPR-based fiber-optic sensor

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Spectroscopy

Background:

• Localized Surface Plasmon Resonance (LSPR) biosensors offer high sensitivity for biomolecule detection.
• Fiber-optic (FO) probes provide a robust platform for remote and miniaturized sensing applications.
• Integrating LSPR with FO technology can lead to novel, portable diagnostic tools.

Purpose of the Study:

• To demonstrate a miniaturized, robust, and portable fiber-optic nanoprobe for DNA detection.
• To develop an integrated solution for real-time DNA hybridization and concentration measurement.
• To assess the sensitivity and selectivity of the developed LSPR-FO nanoprobe.

Main Methods:

• Fabrication of metallic nanostructure arrays on optical fiber end facets using electron beam lithography and lift-off.
• Coupling of localized surface plasmon resonance (LSPR) with fiber-optic (FO) sensing.
• Real-time, label-free quantification of single-strand DNA in aqueous solutions.

Main Results:

• Achieved a limit of detection (LOD) for single-strand DNA around 10 femtomolar (fM).
• Demonstrated high sensitivity and selectivity in DNA quantification.
• The LSPR-FO nanoprobe provided real-time, label-free measurements with low sample volume requirements.

Conclusions:

• The LSPR-coupled FO nanoprobe is a feasible, compact, and low-cost biosensor.
• This technology enables efficient detection of short-strand DNA.
• The developed device holds promise for portable and rapid DNA analysis.