High contrast cleavage detection for enhancing porous silicon sensor sensitivity

Area of Science:

• Nanotechnology and Biosensing
• Optical Interferometry
• Biomedical Diagnostics

Background:

• Traditional biosensors often rely on capturing low-index biological molecules, which can limit sensitivity.
• Optical signal amplification is crucial for developing highly sensitive diagnostic tools.
• Porous silicon (PSi) offers a versatile platform for optical sensing applications.

Purpose of the Study:

• To experimentally implement and validate the high contrast cleavage detection (HCCD) mechanism.
• To demonstrate the use of PSi interferometer sensors for HCCD.
• To assess the sensitivity and reliability of this novel detection approach for biological assays.

Main Methods:

• Utilized porous silicon (PSi) interferometer sensors.
• Implemented the high contrast cleavage detection (HCCD) mechanism.
• Measured reflectance peak shifts after enzymatic cleavage of DNA-quantum dot reporters.

Main Results:

• Achieved the first experimental implementation of the HCCD mechanism using PSi sensors.
• Detected an approximately 2 nm reflectance peak shift upon cleavage of DNA-quantum dot reporters by DNase.
• Observed a signal change 20 times greater than the spectrometer's resolution, consistent with simulations and fluorescence data.

Conclusions:

• The HCCD mechanism provides significant optical signal amplification for biosensing.
• PSi interferometer sensors are effective platforms for implementing HCCD.
• This approach offers a promising pathway for real-time, highly sensitive diagnostic assays based on nucleic acid cleavage.