Dual Protein Corona-Mediated Target Recognition System for Visual Detection and Single-Molecule Counting of Nucleic...

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Diagnostics

Background:

• Nucleic acid detection is vital for diagnostics, but current methods often lack speed or sensitivity for point-of-care applications.
• CRISPR/dCas9 systems offer precise molecular recognition, while gold nanoparticles (AuNPs) provide unique optical properties for sensing.

Purpose of the Study:

• To develop a rapid, highly sensitive, and specific nucleic acid detection platform for point-of-care diagnostics.
• To achieve both visual detection and single-molecule counting of nucleic acids in a one-pot, one-step assay.

Main Methods:

• A dual protein corona-mediated system was designed using CRISPR/dCas9 anchored to AuNPs via guide RNA.
• Target recognition by dCas9 induces aggregation of AuNPs through protein corona interactions.
• Localized surface plasmon resonance (LSPR) of AuNPs was utilized for signal amplification and visualization.

Main Results:

• The platform achieved visual detection of nucleic acid targets as low as 100 aM within 30 minutes.
• Single-molecule detection sensitivity was demonstrated, identifying targets as low as 1 aM (6 molecules in 10 μL) by counting aggregated AuNP spots.
• The system exhibited high sensitivity and specificity suitable for rapid screening of pathogens and cancer biomarkers.

Conclusions:

• The dual protein corona-mediated detection system offers a powerful tool for rapid point-of-care nucleic acid testing.
• The platform's ability to perform single-molecule counting provides unprecedented sensitivity for early disease detection and epidemic surveillance.
• This innovative approach holds significant promise for advancing diagnostics in virology and oncology.