Electrochemical luminescence sensor based on double suppression for highly sensitive detection of glyphosate

An electrochemical luminescence sensor based on a double inhibition strategy for the detection of glyphosate was constructed. In this method, the luminol-gold nanoparticles-L-cysteine-Cu(II) composites (Lu-Au-Lcys-Cu (II)) were used as luminescent reagents, and H2O2 obtained from two-step enzymatic hydrolysis reaction was used as the co-reactive agent of Lu-Au-Lcys-Cu(II). Glyphosate could inhibit the enzymatic reaction, and inhibit catalytic action of the peroxidase-mimicking by competing with L-cysteine to form a complex of glyphosate-Cu (II). The electrochemical luminescence intensity decreased with the increase of glyphosate concentration, under the optimal conditions, the linear range of glyphosate concentration was 0.001 similar to 1.0 mu M, and the limit of detection (LOD) could be as low as 0.5 nM. Importantly, the Electrochemiluminescence sensor also showed acceptable stability and selectivity.