Aptamer-based sensors offer a powerful tool for molecular detection, but the practical implementation of these biosensors is hindered by costly and laborious sequence engineering and chemical modification procedures. The current project first demonstrated that diethylthiatricarbocyanine (Cy7) can stack into DNA three-way junctions (TWJs) in a sequence-independent fashion, greatly altering the dye's absorbance spectrum. The project then designed a TWJ-containing structured library and isolated an aptamer against 3,4-methylenedioxypyrovalerone (MDPV), a synthetic cathinone that is an emerging drug of abuse. This aptamer intrinsically binds Cy7 within its TWJ domain, but MDPV efficiently displaces the dye, resulting in a change in absorbance within seconds. This assay is label-free and detects nanomolar concentrations of MDPV. It also recognizes other synthetic cathinones, offering the potential to detect newly-emerging designer drugs, but does not detect structurally-similar non-cathinone compounds or common cutting agents. Moreover, the project demonstrated that the Cy7-displacement colorimetric assay is more sensitive than a conventional strand-displacement fluorescence assay. The researchers believe this strategy offers an effective generalized approach for the development of sensitive dye-displacement colorimetric assays for other small-molecule targets. (publisher abstract modified)
Downloads
Similar Publications
- Solving Cases of Sudden Unexpected Natural Death in the Young through Comprehensive Postmortem Genetic Testing
- Decreased Accuracy of Forensic DNA Mixture Analysis for Groups with Lower Genetic Diversity
- Quantitative Analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in Cannabis Plants Using the Fast Blue BB (FBBB) and 4-aminophenol (4-AP) Colorimetric Tests