"DNA Origami Traffic Lights" with a Split Aptamer Sensor for a Bicolor Fluorescence Readout

Area of Science:

• Nanotechnology
• Biotechnology
• Molecular Biology

Background:

• DNA origami enables precise nanoscale construction.
• Split aptamers can act as molecular recognition elements.
• Fluorescence energy transfer (FRET) is a sensitive detection mechanism.

Purpose of the Study:

• To develop a DNA origami-based aptasensor for adenosine triphosphate (ATP).
• To integrate a split aptamer recognition unit with a FRET optical module.
• To achieve a bimodal readout using fluorescence and atomic force microscopy (AFM).

Main Methods:

• Embedding a split aptamer for ATP into DNA origami levers.
• Incorporating cyanine-styryl dyes for FRET-based fluorescence readout.
• Utilizing AFM to confirm DNA origami structural transitions.

Main Results:

• ATP binding induced a shape transition in the DNA origami construct.
• A color change from green to red fluorescence indicated ATP presence.
• AFM confirmed the open-to-closed form transition, correlating with fluorescence ratios.
• Bicolor fluorescence allowed real-time monitoring of aptasensor behavior in solution.

Conclusions:

• The developed DNA origami aptasensor provides a bimodal readout for ATP detection.
• The combination of FRET and AFM offers a robust method for aptasensing.
• This approach is valuable for creating custom DNA devices for bioanalytical applications.