Optimization of the structure-switching aptamer-based fluorescence polarization assay for the sensitive tyrosinamide sensing

摘要: In this paper, a structure-switching aptamer assay based on fluorescence polarization (FP) signal transduction approach and dedicated to the L-tyrosinamide sensing was described optimized. A fluorescently labelled complementary strand (CS) of central region used as probe. The effects critical parameters such buffer composition pH, temperature, aptamer:CS stoichiometry, nature dye (Fluorescein (F) or Texas Red (TR)) length CS (15-, 12-, 9- 6-mer) analytical performances were evaluated. Under optimized experimental conditions (10 mM Tris-HCl, 5 MgCl(2) 25 NaCl, pH 7.5 temperature 22°C stoichiometry 1:1), results showed that, for 12-mer CS, F moderately increased method sensitivity in comparison TR label. 9-mer however, did not allow hybrid formation with functional nucleic acid, thus emphasizing importance fluorophore. contrast, same able effectively associate easily displaced upon target binding demonstrated by significant improvement detection limit 250 nM, comparable those reported direct aptasensing methods. present study demonstrates that only but also played preponderant role performance assay, highlighting interdependently controlling these two factors an optimal FP-based platform.