Easy-to-Fabricate and High-Sensitivity LSPR Type Specific Protein Detection Sensor Using AAO Nano-Pore Size Control

Area of Science:

• Nanotechnology
• Biosensing
• Materials Science

Background:

• Optical biosensors are crucial for sensitive analyte detection.
• Anodic aluminum oxide (AAO) nanostructures offer tunable surface properties.
• Improving sensitivity and fabrication efficiency of biosensors is an ongoing challenge.

Purpose of the Study:

• To develop a pore size/pore area-controlled optical biosensor using AAO nanostructures.
• To enhance the sensitivity and selectivity of the biosensor for antigen detection.
• To optimize the fabrication process for faster and easier device production.

Main Methods:

• Fabrication of AAO nanostructures with controlled pore size and area using hard anodization.
• Immobilization of antibodies onto the AAO surface for antigen capture.
• Utilizing localized surface plasmon resonance (LSPR) and interference wave amplification for signal enhancement.
• Evaluating sensor sensitivity by measuring wavelength shifts with refractive index changes.
• Assessing sensor selectivity using C-reactive protein as a heterogeneous antigen.

Main Results:

• Increased pore size and non-pore area of AAO led to enhanced antibody immobilization and higher sensitivity.
• The fabricated sensor achieved high sensitivity, detecting serum amyloid A1 antigen down to 11.8 ag/mL.
• The sensor demonstrated good selectivity, confirmed by its reaction with C-reactive protein.
• Hard anodization significantly reduced fabrication time, enabling quick and easy AAO chip production.

Conclusions:

• The developed AAO-based optical biosensor provides a highly sensitive and selective platform for trace antigen detection.
• Controlling AAO nanostructure morphology (pore size/area) is key to amplifying detection signals.
• The optimized fabrication method using hard anodization offers a practical advantage for rapid device development.