Signal-on Protein Detection via Dye Translocation between Aptamer and Quantum Dot.

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Förster resonance energy transfer (FRET) is a powerful tool for molecular sensing.
• Quantum dots (QDs) offer unique optical properties for biosensing applications.
• Aptamers provide specific molecular recognition capabilities for target analytes.

Purpose of the Study:

• To develop a signal-on biaptameric quantum dot (QD) beacon for protein detection.
• To utilize a unique cyanine dye and QD interaction for Förster resonance energy transfer (FRET) signal generation.
• To demonstrate the capability for distinct aptamer characterization and screening.

Main Methods:

• Construction of a biaptameric beacon with YOYO-3 cyanine dye and carboxyl-QD.
• Induction of aptamer structural folding and sandwich association upon target protein binding.
• Monitoring FRET signal changes due to dye translocation to the QD surface.
• Thrombin detection using the developed beacon and confirmation via cylindrical illumination confocal spectroscopy (CICS).

Main Results:

• A signal-on FRET beacon was successfully constructed.
• The beacon detected thrombin in nanomolar to submicromolar concentrations.
• Dye translocation and target-dependent FRET signal were confirmed.
• The system demonstrated potential for aptamer screening.

Conclusions:

• The proposed beacon offers a simple and rapid method for signal-on FRET protein detection.
• The unique dye-QD interaction facilitates sensitive and specific protein sensing.
• This platform holds promise for high-throughput aptamer screening and characterization.