Parallel Detection of Refractive Index Changes in a Porous Silicon Microarray Based on Digital Images

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Refractive index sensing is crucial for detecting biological and chemical processes.
• Porous silicon (PSi) offers tunable optical properties suitable for sensor applications.
• High-sensitivity and label-free detection methods are needed for biological assays.

Purpose of the Study:

• To develop a high-sensitivity technique for measuring refractive index changes using porous silicon (PSi) microarrays.
• To demonstrate the application of digital imaging for refractive index sensing.
• To enable label-free and parallel detection of refractive index variations.

Main Methods:

• Utilized a porous silicon (PSi) microarray with a microcavity structure.
• Employed digital imaging equipment to capture surface images under He-Ne laser irradiation.
• Calculated the average gray value of the PSi array cell images to determine refractive index changes.

Main Results:

• Achieved a high sensitivity of 10^-4 for refractive index change measurements.
• Demonstrated the capability of digital image analysis to detect subtle refractive index variations.
• Validated the potential for parallel detection of multiple samples simultaneously.

Conclusions:

• The proposed digital imaging technique offers a sensitive and efficient method for refractive index sensing.
• Porous silicon (PSi) microarrays are effective platforms for label-free biosensing.
• This technology holds promise for applications in biological reaction monitoring and diagnostics.