DNA Aptamer-Cyanine Complexes as Generic Colorimetric Small-Molecule Sensors

Aptamers are promising biorecognition elements for sensors. However, aptamer-based assays often lack the requisite levels of sensitivity and/or selectivity because they typically employ structure-switching aptamers with attenuated affinity and/or utilize reporters that require aptamer labeling or which are susceptible to false positives. Dye-displacement assays offer a label-free, sensitive means for overcoming these issues, wherein target binding liberates a dye that is complexed with the aptamer, producing an optical readout. However, broad utilization of these assays has been limited. Here, we demonstrate a rational approach to develop colorimetric cyanine dye-displacement assays that can be broadly applied to DNA aptamers regardless of their structure, sequence, affinity, or the physicochemical properties of their targets. Our approach should accelerate the development of mix-and-measure assays that could be applied for diverse analytical applications.

Automated summary

Aptamers have great potential as biorecognition elements for sensors, but current aptamer-based assays often lack the required sensitivity and selectivity. This study presents a rational approach to develop colorimetric cyanine dye-displacement assays that can be widely applied to DNA aptamers, accelerating the development and use of mix-and-measure assays for various analytical applications.