pH-Responsive and Reversible A-Motif-Based DNA Hydrogel: Synthesis and Biosensing Application

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Biology

Background:

• Designing functional DNA hydrogels requires precise sequence control to prevent self-interference.
• Existing DNA motifs often face challenges with cross-bonding and complex sequence design.

Purpose of the Study:

• To develop a novel DNA hydrogel using the A-motif, which bypasses the need for intricate sequence design.
• To explore the unique properties and potential applications of A-motif DNA hydrogels.

Main Methods:

• Synthesis of A-motif DNA hydrogel using a three-way DNA junction.
• Characterization using electrophoretic mobility shift assay, dynamic light scattering, atomic force microscopy, and scanning electron microscopy.
• Rheological studies to analyze pH-induced sol-to-gel transitions and gelation properties.

Main Results:

• Successfully synthesized a DNA hydrogel with a highly branched morphology using A-motif DNA as a reversible handle.
• Demonstrated quick and reversible pH-induced conformation transformation from monomers to gel.
• Validated the hydrogel's potential in visual detection of pathogenic nucleic acids and in situ formation over mammalian cells.

Conclusions:

• The A-motif DNA hydrogel offers a simplified, sequence-design-free approach to creating functional hydrogels.
• This stimuli-responsive nanostructure has significant potential for diverse biological applications, including biosensing.
• The A-motif's unique properties open new avenues for advanced DNA-based material development.