Ultrasensitive Nucleic Acid Assay Based on AIE-Active Polymer Dots with Excellent Electrochemiluminescence Stability

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Aggregation-induced emission (AIE) Pdots are promising for electrochemiluminescence (ECL) but suffer from unstable emission due to irreversible redox reactions.
• Developing AIE nanomaterials with stable electrochemical properties is crucial for reliable ECL applications.

Purpose of the Study:

• To design and synthesize AIE-active Pdots with reversible redox properties for stable ECL emission.
• To create an ultrasensitive ECL biosensor for miRNA detection.

Main Methods:

• Synthesis of AIE-active Pdots incorporating tetraphenylethene and benzothiadiazole (BT) for reversible redox behavior.
• Electrochemical characterization to confirm reversible and quasi-reversible redox properties.
• Construction of an ECL biosensor utilizing the oxidative-reductive ECL mode.

Main Results:

• The synthesized Pdots demonstrated stable annihilation, reductive-oxidative, and oxidative-reductive ECL signals.
• The Pdots exhibited reversible and quasi-reversible electrochemical behaviors.
• An ultrasensitive ECL biosensor for miRNA-21 detection was achieved with a low detection limit of 32 aM.

Conclusions:

• The developed AIE Pdots with reversible redox properties offer stable ECL emission, overcoming a key limitation in current nanomaterials.
• This work provides a new avenue for designing robust ECL materials and advancing sensitive biosensing technologies.