Carboxylic Carbon Quantum Dots as a Fluorescent Sensing Platform for DNA Detection

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• DNA detection is crucial for disease diagnostics, environmental monitoring, and food safety.
• There is a continuous demand for simple, sensitive, affordable, and selective DNA biosensors.

Purpose of the Study:

• To introduce and evaluate carboxylic carbon quantum dots (cCQD) as nanoquenchers for homogeneous fluorescent nucleic acid detection.
• To assess the performance of two cCQD types (citric acid QD and malic acid QD) in DNA sensing.

Main Methods:

• Development of a homogeneous fluorescent assay utilizing cCQD as nanoquenchers.
• Evaluation of DNA detection performance, including detection range and specificity, using two cCQD variants.
• Exploitation of differential adsorption of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) onto cCQD surfaces.

Main Results:

• Both citric acid QD and malic acid QD demonstrated a detection range of at least 3 orders of magnitude for nucleic acid detection.
• The cCQD-based assay exhibited the capability to distinguish single-base mismatches in DNA.
• The sensing principle relies on the varying adsorption affinities of ssDNA and dsDNA onto cCQD.

Conclusions:

• Carboxylic carbon quantum dots (cCQD) are effective nanoquenchers for homogeneous fluorescent DNA biosensing.
• The developed cCQD-based method offers high sensitivity, a broad detection range, and specificity for DNA detection.
• These findings support the use of cCQD in the development of advanced DNA biosensors for diverse applications.