A Broadly Generalizable Dye for Colorimetric Aptamer-Based Sensors

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Diagnostics

Background:

• Aptamer-based dye-displacement assays offer simple, rapid, and robust analyte detection via color change.
• These assays rely on dye displacement from aptamers upon target binding, leading to dye aggregation and absorbance shifts.
• The generalizability of existing dyes with diverse aptamers remains a challenge.

Purpose of the Study:

• To evaluate the compatibility of common cyanine dyes (Cy7, MTC) with a panel of 105 DNA aptamers.
• To identify a novel dye with broad applicability in aptamer-based dye-displacement assays.
• To enable 'plug-and-play' development of colorimetric sensors for various targets.

Main Methods:

• Tested 105 small-molecule-binding DNA aptamers for compatibility with cyanine dyes Cy7 and MTC.
• Screened a large library of dyes to identify a broadly applicable dye for displacement assays.
• Validated the performance of the identified dye (X-732-91B) with 105 aptamer-target pairs.

Main Results:

• Approximately 50% of tested aptamers were incompatible with Cy7 and MTC dyes.
• Identified X-732-91B, an asymmetric cyanine dye, demonstrating high generalizability.
• X-732-91B successfully worked with 95% of the aptamer-target pairs, providing rapid, measurable signals.

Conclusions:

• The identified dye X-732-91B overcomes limitations of existing dyes in aptamer-based assays.
• This breakthrough facilitates the development of versatile aptamer-based colorimetric sensors.
• Potential applications span medical diagnostics, environmental monitoring, quality control, and forensics.