A Carbon-Dot-Based Fluorescent Nanosensor for Simple Visualization of Bacterial Nucleic Acids

Area of Science:

• Nanotechnology
• Biomedical Diagnostics
• Molecular Biology

Background:

• Accurate nucleic acid sensing is crucial for disease biomarker detection and diagnosis.
• Existing methods often lack simplicity, speed, or portability for widespread clinical use.

Purpose of the Study:

• To develop a simple, facile, and visual fluorescent nanosensor for nucleic acid detection.
• To enable point-of-care diagnostics using smartphone-compatible imaging and analysis.

Main Methods:

• Fabrication of carbon dot nanoparticles via microwave pyrolysis of polyethylenimine.
• Utilizing the photoluminescent properties of carbon dots for precipitation-based DNA sensing.
• Smartphone imaging and analysis for quantification of target DNA oligonucleotides.

Main Results:

• The carbon dot nanosensor formed visible precipitates upon binding with target DNA.
• Successful fluorescent sensing and visualization of oligonucleotides with high sensitivity (≈100 pmol).
• Demonstrated application in detecting antibiotic-resistance gene (KPC-2) in bacterial DNA.

Conclusions:

• A simple and effective carbon dot-based fluorescent nanosensor for nucleic acid detection has been developed.
• The assay is suitable for visualizing and quantifying minimal amounts of DNA, applicable to various targets.
• This platform shows significant potential for bedside and point-of-care diagnostic applications.