Engineering Colorimetric Aptazyme Sensors for Detecting High Levels of PFAS

Per/polyfluoroalkyl substances (PFAS) make up a concerning class of environmental contaminants across the world. Corresponding health concerns and increasing exposure to PFAS warrant the development of portable detection methods for on-site testing to increase testing frequency, minimize PFAS exposure, and guide remediation efforts. This work aims to demonstrate the potential of using functional nucleic acids (FNAs) as a biosensing platform for such purposes. Specifically, we tested multiple aptazyme constructs to program signal amplification into a PFOA aptasensor to increase the sensitivity for PFOA detection. The results show that sensors were comparable to the aptasensor but used a simpler colorimetric readout compared to fluorescence. Interestingly, the selectivity of the aptazyme sensor was altered to detect longer chain PFAS. Though the primary goal of this research is to improve PFAS detection using aptazyme sensors by improving sensitivity and using a colorimetric readout, more broadly, this work aims to develop generalizable design rules for constructing aptazyme sensors.