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Sensing Characteristics of SARS-CoV-2 Spike Protein Using Aptamer-Functionalized Si-Based Electrolyte-Gated
Seonghwan Shin1, Sangwon Kim2, Wonyeong Choi1
1Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Biosensors
|March 27, 2024
Summary
This study shows that silicon-based electrolyte-gated transistors (EGTs) can detect SARS-CoV-2 spike proteins with high sensitivity. The developed aptamer-functionalized EGTs offer a promising method for rapid and accurate viral detection.
Area of Science:
- Nanotechnology and Biosensing
- Materials Science
- Biophysics
Background:
- Accurate and sensitive detection of SARS-CoV-2 spike protein is crucial for disease diagnosis and monitoring.
- Electrolyte-gated transistors (EGTs) offer a potential platform for label-free biosensing due to their high sensitivity.
- Functionalization of EGTs with specific bioreceptors is key to achieving targeted detection of viral proteins.
Purpose of the Study:
- To investigate the sensing performance of top-down-fabricated silicon-based EGTs for SARS-CoV-2 spike protein detection.
- To evaluate the sensitivity and limit of detection (LOD) of the EGTs.
- To analyze the sensing mechanism using a lumped-capacitive model.
Main Methods:
- Fabrication of silicon-based electrolyte-gated transistors (EGTs).
- Functionalization of EGTs with aptamers as specific receptors for SARS-CoV-2 spike protein.
- Electrical characterization of EGTs in the subthreshold and linear regimes.
- Analysis of sensing data using a lumped-capacitive model incorporating dipole potential and functionalized layer capacitance.
Main Results:
- EGTs exhibited excellent intrinsic characteristics and higher sensitivity in the subthreshold regime compared to the linear regime.
- Achieved a limit of detection (LOD) as low as 0.94 pg/mL for current sensitivity and 20 pg/mL for voltage sensitivity.
- A lumped-capacitive model effectively explained the sensing responses, considering effective dipole potential and capacitance of the functionalized layer.
- The aptamer-functionalized EGT demonstrated high sensitivity even in a 10 mM phosphate-buffered saline (PBS) solution.
Conclusions:
- Silicon-based EGTs functionalized with aptamers are highly sensitive and effective for detecting SARS-CoV-2 spike proteins.
- The subthreshold regime of EGTs provides enhanced sensitivity for biosensing applications.
- These findings highlight the potential of Si-based EGTs as a promising platform for developing advanced diagnostic tools for viral detection.
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