Sensor Based on Aptamer Folding to Detect Low-Molecular Weight Analytes.

Aptamers have emerged as promising biorecognition elements in the development of biosensors. The present work focuses on the application of quartz crystal microbalance with dissipation monitoring (QCM-D) for the enantioselective detection of a low mol. wt. target mol. ({\textless}200 Da) by aptamer-based sensors. While QCM-D is a powerful technique for label-free, real-time characterization and quantification of mol. interactions at interfaces, the detection of small mols. interacting with immobilized receptors still remains a challenge. The authors take advantage of the aptamer conformational changes upon the target binding that induces displacement of water acoustically coupled to the sensing layer. As a consequence, this phenomenon leads to a significant enhancement of the detection signal. The methodol. is exemplified with the enantioselective recognition of a low mol. wt. model compd., L-tyrosinamide (L-Tym). QCM-D monitoring of L-Tym interaction with the aptamer monolayer leads to an appreciable signal that can be further exploited for anal. purposes or thermodn. studies. Furthermore, in situ combination of QCM-D with spectroscopic ellipsometry unambiguously demonstrates that the conformational change induces a nanometric decrease of the aptamer monolayer thickness. Since QCM-D is sensitive to the whole mass of the sensing layer including water that is acoustically coupled, a decrease in thickness of the highly hydrated aptamer layer induces a sizable release of water that can be easily detected by QCM-D. [on SciFinder(R)]


Sensor Based on Aptamer Folding to Detect Low-Molecular Weight Analytes.
Type de publication
Article de revue
Année de publication
Anal. Chem. (Washington, DC, United States)
Soumis le 12 avril 2018