Construction of a novel fluorescent probe for sensitive determination of glyphosate in food and imaging living cells

Abstract

Glyphosate is a widely used broad-spectrum herbicide in agriculture and horticulture to control a variety of weeds and undesirable plants. However, the excessive use of glyphosate has raised a number of environmental and human health concerns. It is urgent to develop tools to detect glyphosate. Herein, a novel dual-signal probe CCU–Cu²⁺ was designed and synthesized on the basis of CCU. CCU exhibited excellent selectivity and great sensitivity for Cu²⁺ which were based on both fluorescence “turn-off” reaction and comparative color visualisation methods. Due to the strong chelating ability of glyphosate on Cu²⁺, the CCU–Cu²⁺ complex was applied to glyphosate detection in practical samples. The experimental results in vitro showed that the CCU–Cu²⁺ complex was highly selective and rapid, with a low detection limit (1.6 μM), and could be recognised by the naked eye in the detection of glyphosate. Based on the excellent properties of the CCU–Cu²⁺ complex, we also constructed a smartphone-assisted detection sensing system for glyphosate detection, which has the advantages of precision, sensitivity, and high interference immunity. Moreover, the CCU–Cu²⁺ complex was also successfully employed for exogenous glyphosate imaging in living cells. These characteristics demonstrated that CCU–Cu²⁺ holds significant potential for detection and imaging of glyphosate in bio-systems.