Plasmonic Cross-Linking Colorimetric PCR for Simple and Sensitive Nucleic Acid Detection

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Diagnostics

Background:

• Point-of-care (POC) nucleic acid assays are crucial for disease surveillance and control.
• Plasmonic photothermal polymerase chain reaction (PPT-PCR) is effective but lacks simple analysis methods for POC use.

Purpose of the Study:

• To develop a novel, simple, and sensitive assay for POC nucleic acid detection.
• To integrate PPT-PCR with gold nanoparticle (AuNP)-based colorimetry for visual readout.

Main Methods:

• Developed a plasmonic cross-linking colorimetric PCR (PPT-ccPCR) assay.
• Utilized plasmonic magnetic nanoparticles (PMNs) for PPT-PCR and AuNPs for cross-linking colorimetry.
• Employed a magnetic field to concentrate AuNP-PMN complexes for colorimetric detection.

Main Results:

• Visual detection of target DNA at concentrations as low as 5 copies/μL within 40 minutes.
• Achieved a limit of detection of 1.8 copies/μL using absorption signals.
• Demonstrated a simple, sensitive, and instrument-free detection strategy.

Conclusions:

• The PPT-ccPCR assay offers a promising solution for rapid, low-cost POC pathogen detection.
• This method has high potential for clinical diagnostics and disease surveillance applications.
• The assay eliminates the need for expensive instrumentation, enhancing accessibility.