Molecular Diagnostic System Using Engineered Fusion Protein-Conjugated Magnetic Nanoparticles

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Nanotechnology

Background:

• Rapid and sensitive detection of viral nucleic acids is crucial for controlling infectious disease outbreaks.
• Existing diagnostic methods often require complex procedures and specialized equipment, limiting their use in point-of-care settings.

Purpose of the Study:

• To develop a universal, simple, and highly sensitive molecular diagnostic strategy for rapid detection of viral nucleic acids.
• To engineer a novel magnetic nanoparticle (MNP) conjugate using a MagR-MazE fusion protein for enhanced molecular diagnostics.

Main Methods:

• Conjugation of magnetic nanoparticles (MNPs) with a novel MagR-MazE fusion protein.
• Development of a lateral flow assay for visual detection of nucleic acid targets.
• Detection of polymerase chain reaction (PCR) products of 16S ribosomal RNA (rRNA) and 2019-nCoV-N gene.

Main Results:

• The MNP-fusion protein conjugate was easily generated with minimal chemical reagents.
• The assay allowed for naked-eye visualization of results in 5 minutes, independent of target oligonucleotide sequences.
• A low limit of detection (LoD) of 0.013 ng/μL for dsDNA was achieved.
• Sensitive detection of PCR products for 16S rRNA and 2019-nCoV-N was demonstrated.

Conclusions:

• The developed MagR-MazE fusion protein-conjugated MNP system offers a simple, rapid, sensitive, and versatile nucleic acid detection method.
• This strategy is suitable for point-of-care testing and has broad applicability in various fields requiring rapid on-site diagnosis.