Smartphone-Based Peptide Nucleic Acid (PNA) Probe-Assisted Potentiometric Biosensor for Point-of-Care Testing of...

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Molecular Diagnostics

Background:

• Traditional DNA probes in biosensors can cause fouling due to electrostatic interactions with biomolecules.
• Developing sensitive and rapid detection methods for SARS-CoV-2 is crucial for pandemic control.

Purpose of the Study:

• To develop a novel potentiometric biosensor for sensitive and rapid detection of SARS-CoV-2.
• To utilize electrostatically neutral peptide nucleic acids (PNA) as an antifouling strategy.
• To integrate the biosensor with a smartphone for portable diagnostics.

Main Methods:

• Fabrication of a screen-printed carbon electrode modified with a plasticized polymeric membrane.
• Functionalization of magnetic beads with neutral PNA probes specific to SARS-CoV-2.
• Detection via potentiometric response after magnetic nanoparticle incubation and magnetic field application.
• Optimization of various assay parameters and validation in human saliva samples.

Main Results:

• The biosensor achieved a linear detection range of 1.0 × 10⁻¹⁵–1.0 × 10⁻¹¹ M for SARS-CoV-2 DNA.
• A low limit of detection (LOD) of 4.9 × 10⁻¹⁶ M was obtained.
• High recovery rates (96–98%) were observed in human saliva samples.
• Successful proof-of-concept demonstration using a smartphone-integrated analyzer.

Conclusions:

• The developed PNA-based biosensor offers a promising antifouling strategy for sensitive SARS-CoV-2 detection.
• The biosensor demonstrates potential for rapid and portable COVID-19 screening in biological samples.
• This approach provides a new concept for developing next-generation biosensors.