Highly sensitive nano-porous lattice biosensor based on localized surface plasmon resonance and interference

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Existing biosensors face limitations in sensitivity, selectivity, and dynamic range.
• Nanostructured anodized aluminum oxide (AAO) offers unique optical properties.
• Combining optical interference and localized surface plasmon resonance (LSPR) can enhance biosensor performance.

Purpose of the Study:

• To design and fabricate a highly sensitive biosensor utilizing nanostructured AAO substrates.
• To leverage dual optical properties (interference and LSPR) for improved biosensing.
• To demonstrate the sensor's capability for detecting C-reactive protein (CRP) antigen.

Main Methods:

• Fabrication of uniform periodic nanopore lattice AAO templates via two-step anodizing.
• Deposition of a gold coating onto the AAO substrate.
• Immobilization of C-reactive protein (CRP) antibody on the gold-coated AAO.
• Detection of CRP antigen (Ag) binding via monitoring reflectance shifts.

Main Results:

• The gold-deposited AAO substrate exhibited both optical interference and LSPR.
• The biosensor demonstrated high selectivity for CRP antigen detection.
• The sensor successfully measured CRP antigen concentrations down to 1 fg/ml.

Conclusions:

• The proposed AAO-based biosensor offers a simple, fast, and highly sensitive method for protein detection.
• The combination of optical interference and LSPR on AAO substrates overcomes limitations of traditional biosensors.
• This technology holds promise for real-time protein analysis in various applications.