DNA transducer-triggered signal switch for visual colorimetric bioanalysis.

Area of Science:

• Biomolecular Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Developing sensitive and specific biosensors is crucial for detecting various biomolecules and pathogens.
• Existing methods often require complex instrumentation or lack versatility.
• Colorimetric assays offer a simple and accessible detection platform.

Purpose of the Study:

• To develop a simple, versatile, and sensitive colorimetric biosensor.
• To detect a wide range of biomolecules, including oligonucleotides and aptamer targets.
• To apply the biosensor for the detection of pathogenic bacteria, specifically S. pneumoniae.

Main Methods:

• Utilized catalyzed hairpin assembly (CHA) for signal amplification.
• Integrated a signal transducer with CHA to generate G-rich DNA.
• Formed G-quadruplex/hemin complexes to mimic horseradish peroxidase activity for colorimetric detection.

Main Results:

• Achieved a detection limit of 32 pM for synthetic target DNA.
• Demonstrated successful detection of S. pneumoniae as low as 156 CFU mL(-1).
• Showcased high specificity against related bacteria and enabled naked-eye visual analysis in clinical samples.

Conclusions:

• The developed colorimetric biosensor is highly sensitive, specific, and versatile.
• The CHA-based amplification strategy provides a robust platform for biomolecule and pathogen detection.
• This method offers potential for point-of-care diagnostics and diverse analytical applications.