Sensitive single-color fluorescence "off-on" switch system for dsDNA detection based on quantum dots-ruthenium...

Area of Science:

• Biochemistry
• Analytical Chemistry
• Nanotechnology

Background:

• Accurate and rapid detection of double-stranded DNA (dsDNA) is crucial for diagnostics.
• Existing methods may lack sensitivity, speed, or require complex sample preparation.

Purpose of the Study:

• To develop a novel, sensitive, and rapid dsDNA detection method using a single-color fluorescence "off-on" switch system.
• To evaluate the system's performance, selectivity, and potential clinical applicability.

Main Methods:

• Preparation of water-soluble glutathione-capped Cadmium Telluride Quantum Dots (CdTe QDs).
• Utilizing a fluorescence "off-on" mechanism where dsDNA addition triggers fluorescence recovery.
• Testing selectivity against single-stranded DNA (ssDNA), RNA, and Bovine Serum Albumin (BSA).

Main Results:

• Detection of dsDNA down to 10 pg/mL using 0.5 nM CdTe QDs.
• No interference observed from ssDNA, RNA, or BSA, indicating high selectivity.
• Accurate detection of hepatitis B virus (HBV) dsDNA in patient samples, comparable to quantitative PCR, with improved accuracy for low concentrations.

Conclusions:

• The developed "off-on" switch system offers a simple, fast, sensitive, and selective method for dsDNA detection.
• The system does not require chemical conjugation or probe labeling, simplifying the detection process.
• Demonstrated potential for clinical applications, particularly in detecting viral dsDNA like HBV.