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In Vitro Selection of Aptamers to Differentiate Infectious from Non-Infectious Viruses
Published on: September 7, 2022
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Smartphone-Integrated User-Friendly Electrochemical Biosensor Based on Optimized Aptamer Specific to SARS-CoV-2 S1
Arzum Erdem1, Huseyin Senturk1, Esma Yildiz1
1Department of Analytical Chemistry, Faculty of Pharmacy, Ege University, 35040 İzmir, Türkiye.
Sensors (Basel, Switzerland)
|November 13, 2025
Summary
A novel electrochemical biosensor uses optimized aptamers to detect the SARS-CoV-2 S1 protein, enabling rapid and sensitive COVID-19 diagnostics. This low-cost, portable device shows high selectivity and potential for point-of-care applications.
Area of Science:
- Biomedical Engineering
- Analytical Chemistry
- Infectious Disease Diagnostics
Background:
- COVID-19, caused by SARS-CoV-2, presents significant global health challenges requiring rapid diagnostic solutions.
- The SARS-CoV-2 spike (S) protein, specifically the S1 subunit, is crucial for viral entry and serves as a key biomarker for early detection.
- Existing diagnostic methods face limitations in speed, cost, and portability for widespread, timely screening.
Purpose of the Study:
- To develop a disposable, low-cost, and portable electrochemical biosensor for the sensitive and selective detection of SARS-CoV-2 S1 protein.
- To optimize aptamer-based recognition and electrochemical signal transduction for enhanced diagnostic performance.
- To evaluate the biosensor's potential for point-of-care (POC) use in diagnosing COVID-19.
Main Methods:
- Fabrication of a disposable electrochemical biosensor using pencil graphite electrodes (PGEs) functionalized with optimized aptamers (Optimers).
- Optimization of critical parameters including aptamer concentration, interaction time, redox probe concentration, and immobilization time using differential pulse voltammetry (DPV).
- Validation of sensor performance using ferri/ferrocyanide redox probe and assessment of selectivity against related antigens and in artificial saliva.
Main Results:
- The optimized biosensor demonstrated an ultralow limit of detection (LOD) of 18.80 ag/mL in buffer and 14.42 ag/mL in artificial saliva.
- Achieved a wide linear detection range from 10-1 to 104 fg/mL, indicating broad applicability.
- Exhibited excellent selectivity against hemagglutinin antigen and MERS-CoV-S1 protein, confirming specificity for SARS-CoV-2 S1.
Conclusions:
- This study presents the first voltammetric biosensor using optimized aptamers for SARS-CoV-2 S1 detection on disposable PGEs.
- The developed biosensor offers a robust, field-deployable platform for early COVID-19 diagnostics with high sensitivity and selectivity.
- Integration with a smartphone-connected portable potentiostat highlights its strong potential for accessible point-of-care testing.
Keywords:
COVID-19SARS-CoV-2 S1 proteindifferential pulse voltammetryelectrochemical biosensorinfectious diseaseoptimized-aptamersmartphone-connected potentiostatMore Related Videos
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