A facile optical sensing strategy for glyphosate detection based on structure-switching signaling aptamers

A facile and highly specific optical sensing strategy is established for glyphosate (GLYP) detection using structure-switching signaling aptamers (F-SSSAs) with fluorescence signal reporting functionality. The strategy involves two domains: the FITC-labeled signal transduction domain for fluorescence signal reporting, while the functional domain (specific structure-switching aptamers) controls the target recognition. Graphene oxide (GO) works as a robust F-SSSAs quencher in the absence of GLYP. However, the F-SSSAs structure is switched in the presence of GLYP, prominently affecting the interaction with GO. The fluorescence of the structure-switching signaling aptamer-based sensing system is subsequently restored. The present strategy exhibits two dynamic linear relationships for GLYP detection in the ranges 0.2 to 80 ng·mL⁻¹ and 100 to 800 ng·mL⁻¹, with a low detection limit (LOD) of 0.07 ng·mL⁻¹. Significantly, the proposed sensing system has been successfully utilized to detect GLYP in water, soil, and rice, demonstrating its potential applications in GLYP monitoring.