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 and 100 to 800 ng·mL, with a low detection limit (LOD) of 0.07 ng·mL. Significantly, the proposed sensing system has been successfully utilized to detect GLYP in water, soil, and rice, demonstrating its potential applications in GLYP monitoring.