Solid-Phase Extraction and Enhanced Amplification-Free Detection of Pathogens Integrated by Multifunctional...

Area of Science:

• Molecular Diagnostics
• Biosensing Technology
• CRISPR-based Systems

Background:

• Resource-limited settings require effective diagnostic tools for infection management.
• CRISPR-based biosensing offers next-generation diagnostics, including point-of-care (POC) testing.
• Existing CRISPR diagnostics often require preamplification, limiting their efficiency.

Purpose of the Study:

• To develop a novel CRISPR-Cas12a nucleic acid assay that integrates multiple functions.
• To enhance diagnostic sensitivity and negate the need for preamplification.
• To create a versatile platform for point-of-care infectious disease detection.

Main Methods:

• Developed the Solid-Phase Extraction and Enhanced Detection Assay integrated by CRISPR-Cas12a (SPEEDi-CRISPR).
• Utilized Cas12a-coated magnetic beads for solid-phase extraction, enrichment, and fluorogenic detection.
• Integrated target identification, sequence-specific enrichment, and signal generation into a single platform.

Main Results:

• Achieved detection limits from picomolar (pM) to femtomolar (fM) levels without preamplification.
• Demonstrated high specificity, distinguishing HPV-18 from HPV-16 and Parvovirus B19.
• Detected HPV-18 at concentrations as low as 2.3 fM (100 min) and 4.7 fM (60 min).
• Successfully coupled the assay with smartphone-based fluorescence detection and lateral flow assays for POC applications.

Conclusions:

• The SPEEDi-CRISPR assay offers a preamplification-free approach for highly sensitive nucleic acid detection.
• This integrated platform leverages CRISPR-Cas12a's capabilities for efficient extraction, enrichment, and detection.
• The assay shows promise for developing advanced, rapid, and accessible CRISPR diagnostics for infectious diseases.