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Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Evanescent field response to immunoassay layer thickness on planar waveguides
Applied Physics Letters
|June 17, 2009
Summary
This study investigated a photonic biosensor for detecting C-reactive protein. Higher ridge heights on the waveguide showed greater optical intensity modulation, improving sensitivity for antigen detection.
Area of Science:
- Photonics
- Biosensing
- Biochemistry
Background:
- Planar waveguide photonic biosensors offer sensitive detection methods.
- C-reactive protein (CRP) is a key biomarker for inflammation.
- Controlling waveguide properties is crucial for optimizing biosensor performance.
Purpose of the Study:
- To investigate the response of a compact photonic immunoassay biosensor to varying C-reactive protein concentrations.
- To evaluate the impact of waveguide ridge height on biosensor sensitivity and performance.
Main Methods:
- Utilized a planar waveguide photonic immunoassay biosensor.
- Employed near-field scanning optical microscopy (NSOM) for surface analysis.
- Performed simulations using the Beam Propagation Method (BPM).
Main Results:
- Optical intensity modulation of 1.7%/nm and 3.3%/nm was observed for 16.5 nm and 10 nm ridge heights, respectively.
- Simulations using BPM accurately predicted experimental sensitivities.
- Leaky mode interference was observed within and after the adlayer region.
Conclusions:
- Waveguide ridge height significantly influences the sensitivity of photonic immunoassay biosensors.
- The studied biosensor design shows promise for sensitive C-reactive protein detection.
- BPM simulations are a valuable tool for predicting and optimizing biosensor behavior.
