Alkanethiol-functionalized terahertz metamaterial as label-free, highly-sensitive and specific biosensor

Area of Science:

• Metamaterials science
• Biosensing technology
• Terahertz spectroscopy

Background:

• Specific biorecognition is crucial for biological processes, necessitating sensitive, label-free biosensors.
• Metamaterials offer unique properties suitable for advanced biosensing applications.

Purpose of the Study:

• To fabricate a label-free and specific biosensor for streptavidin-agarose (SA) detection.
• To investigate the application of terahertz metamaterials for sensitive biomolecule detection.

Main Methods:

• Fabrication of a terahertz metamaterial sensor functionalized with octadecanthiols and biotins.
• Utilizing both low and high frequency resonant modes for SA detection.
• Investigating the effect of substrate refractive index on sensor sensitivity.

Main Results:

• The metamaterial sensor demonstrated label-free detection of SA.
• A significant redshift (up to 6.76 GHz) was observed for the high-frequency resonant mode upon SA adsorption.
• Sensitivity was enhanced by replacing a high refractive-index substrate with a low refractive-index one.

Conclusions:

• Terahertz metamaterials functionalized with biotin provide a sensitive platform for SA detection.
• Both LC oscillation and plasmonic dipole modes are sensitive to micro-environmental changes.
• Optimizing metamaterial design can further improve biosensor sensitivity for various biomolecules.