Universal Design of Structure-Switching Aptamers with Signal Reporting Functionality

Area of Science:

• Biotechnology
• Molecular Biology
• Analytical Chemistry

Background:

• Structure-switching aptamers (SSAs) are valuable for biosensor development but are difficult to generate.
• Existing methods for SSA creation are challenging and limited in scope.

Purpose of the Study:

• To develop a simple, universal strategy for engineering aptamers into SSAs with signal reporting capabilities.
• To create a novel biosensor platform based on DNAzyme G-quadruplexes (G4s) and SSAs.

Main Methods:

• Engineered aptamers into G4-SSAs, combining a G4 DNAzyme for signal transduction and an aptamer for target binding.
• Utilized the change in G4 DNAzyme activity upon target binding for detection.
• Demonstrated colorimetric and fluorescence-based detection methods.

Main Results:

• The G4-SSA constructs exhibit high peroxidase activity in the absence of target, which decreases upon target binding.
• Achieved sensitive and specific detection of diverse targets, including Hg2+, thrombin, and small molecules.
• Demonstrated the versatility of the G4-SSA engineering strategy across different aptamers and targets.

Conclusions:

• The developed G4-SSA strategy provides a broadly applicable and accessible method for creating novel aptamer-based biosensors.
• This approach simplifies SSA generation and enhances the utility of aptamer biosensor technology.