Quantum Dot-DNA FRET Conjugates for Direct Analysis of Methylphosphonic Acid in Complex Media

Steven M E Demers; Wendy W Kuhne; Ashlee R Swindle; Don D Dick; Kaitlin J Coopersmith

doi:10.1021/acsomega.3c02173

Quantum Dot-DNA FRET Conjugates for Direct Analysis of Methylphosphonic Acid in Complex Media

ACS Omega. 2023 Jun 9;8(25):23017-23023. doi: 10.1021/acsomega.3c02173. eCollection 2023 Jun 27.

Authors

Steven M E Demers¹, Wendy W Kuhne¹, Ashlee R Swindle¹, Don D Dick¹, Kaitlin J Coopersmith¹

Affiliation

¹ Global Security Directorate, Savannah River National Laboratory, P.O. Box A, Aiken, South Carolina 29808, United States.

Abstract

Rapid detection of nerve agents from complex matrices with minimal sample preparation is essential due to their high toxicity and bioavailability. In this work, quantum dots (QDs) were functionalized with oligonucleotide aptamers that specifically targeted a nerve agent metabolite, methylphosphonic acid (MePA). These QD-DNA bioconjugates were covalently linked to quencher molecules to form Förster resonance energy transfer (FRET) donor-acceptor pairs that quantitatively measure the presence of MePA. Using the FRET biosensor, the MePA limit of detection was 743 nM in artificial urine. A decrease in the QD lifetime was measured upon DNA binding and was recovered with MePA. The biosensor's flexible design makes it a strong candidate for the rapid detection of chemical and biological agents for deployable, in-field detectors.