DNA-Engineered CsPbBr₃ Superlattices with Enhanced Electronic Coupling for High-Performance Electrochemiluminescence...

Area of Science:

• Materials Science
• Nanotechnology
• Biochemistry

Background:

• Perovskite quantum dots (PQDs), especially CsPbBr3 QDs, show great potential for electrochemiluminescence (ECL) due to superior optical characteristics.
• A major hurdle for PQDs is their instability in aqueous solutions, which limits their practical use in biosensing.
• Enhancing ECL efficiency while maintaining stability in water is crucial for advancing PQD technology.

Purpose of the Study:

• To develop a strategy for stabilizing CsPbBr3 QDs in aqueous environments.
• To improve the electrochemiluminescent (ECL) performance of CsPbBr3 QDs.
• To create a highly sensitive ECL biosensor for miRNA detection.

Main Methods:

• Utilized DNA nanosheets as templates for the self-assembly of CsPbBr3 QDs into 2D superlattices.
• Characterized the structure and charge transfer using Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS).
• Evaluated the ECL intensity, efficiency, and stability of the CsPbBr3/DNA nanosheet (NS) complexes in aqueous conditions.

Main Results:

• Achieved long-range ordered arrangement of CsPbBr3 QDs on DNA NSs, enhancing charge-carrier transport.
• Demonstrated a 2.5-fold increase in ECL intensity and a 65.5% ECL efficiency for CsPbBr3/DNA NSs compared to unassembled QDs.
• Showcased remarkable stability, retaining 83.3% of initial ECL intensity after 10 days in water.
• Successfully developed a ratiometric ECL biosensor for miRNA-221 detection with an ultra-low detection limit of 6.05 aM.

Conclusions:

• The DNA nanosheet templating strategy effectively addresses the aqueous instability of CsPbBr3 QDs while enhancing their ECL efficiency.
• This approach significantly improves the performance and durability of PQDs for advanced applications.
• The developed ECL biosensor demonstrates high sensitivity and stability, paving the way for practical miRNA detection.