On-chip multivariant COVID 19 photonic sensor based on silicon nitride double-microring resonators

Area of Science:

• Photonics
• Biosensing
• Molecular Diagnostics

Background:

• Emerging infectious diseases like COVID-19 necessitate rapid and reliable detection methods.
• Current diagnostic tools face challenges in speed, sensitivity, and scalability.
• Development of novel biosensors is crucial for effective disease surveillance and control.

Purpose of the Study:

• To develop a chip-scale photonic sensing device for the rapid detection of SARS-CoV-2.
• To demonstrate the efficacy of a silicon-nitride double microring resonator (MRR) for biosensing applications.
• To establish a label-free, CMOS-compatible platform for pathogen detection.

Main Methods:

• Fabrication of a silicon-nitride double microring resonator (MRR) sensor.
• Surface functionalization of one MRR with DNA primers specific to SARS-CoV-2 RNA.
• Utilizing the second MRR as a reference for differential measurement.
• Testing sensor performance with varying concentrations of SARS-CoV-2 complementary RNA.

Main Results:

• The photonic sensor successfully detected SARS-CoV-2 RNA fragments at concentrations as low as 10 cp/μL.
• Achieved a high sensitivity of 750 nm/RIU, indicating excellent response to target molecules.
• Demonstrated label-free detection, eliminating the need for secondary labeling agents.
• Confirmed independence from environmental factors like temperature and pressure.

Conclusions:

• The developed MRR-based photonic sensor shows significant promise for the rapid and sensitive detection of SARS-CoV-2.
• The platform is label-free, small form factor, CMOS compatible, and robust against environmental variations.
• This technology can be extended for detecting other viral genes, pathogens, and biomarkers.