Programmed pH-Driven Reversible Association and Dissociation of Interconnected Circular DNA Dimer Nanostructures

Area of Science:

• Supramolecular Chemistry
• Nanotechnology
• Biochemistry

Background:

• Development of dynamic and responsive nanomaterials is crucial for advanced applications.
• DNA nanotechnology offers precise control over nanoscale assembly and function.
• pH-responsive elements are key for creating switchable molecular systems.

Purpose of the Study:

• To present pH-driven reversible assembly and dissociation of interlocked circular DNA dimers.
• To demonstrate pH-responsive nucleic acid bridges and locks for controlling DNA nanostructures.
• To explore the use of these DNA dimers as scaffolds for nanoparticle assembly.

Main Methods:

• Design and synthesis of circular DNA dimers interconnected by pH-responsive nucleic acid bridges.
• Utilizing pH-dependent triplex formation (C-G·C(+) and T-A·T) to control assembly and dissociation.
• Monitoring structural changes using time-dependent fluorescence and gel electrophoresis.
• Implementing dimer DNA structures as scaffolds for gold nanoparticle assembly.

Main Results:

• Demonstrated reversible dissociation of DNA dimers at pH 5.0 and reassembly at pH 7.0 via C-G·C(+) triplexes.
• Showcased dissociation at pH 10.0 and bridging at pH 7.0 using T-A·T triplexes.
• Confirmed pH-programmed opening of locks leading to isomeric dimer structures.
• Successfully assembled gold nanoparticle dimers using the DNA structures as scaffolds.

Conclusions:

• Switchable, pH-responsive circular DNA dimers can be reversibly assembled and dissociated.
• The system offers precise control over nanostructure reconfiguration through pH modulation.
• These DNA nanostructures serve as versatile scaffolds for creating functional nanoparticle assemblies.