A Cu2+-Cu/glassy carbon system for glyphosate determination

AGUIRRE, MARÍA DEL CARMEN; URRETA, SILVIA E.; GOMEZ, CÉSAR G.

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Año: 2019 vol. 284 p. 675 - 675

0925-4005

u° electrocrystallization onto glassy carbon (GC) at potentials between −0.4 V and −0.7 V is consistent with a 3D progressive nucleation mechanism and diffusion-controlled growth. Cu/GC electrode prepared at −0.6 V is applied to the detection of a widely used herbicide such as glyphosate (Glyp). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods are applied in the Glyp determination in acetic acid buffer aqueous solution (ABS) at pH 5 or pH 6. Optimal herbicide detection properties are found for this electrode, arising from Cu°/Cu+ and Cu+/Cu2+ couples. An interesting phenomenon is detected by the DPV method, with Cu/GC electrode in presence of (0.03?0.2 mM) Cu2+ into the ABS at pH 6, when glyphosate is added. For an oxidation potential of −0,015 V vs. Ag/AgCl for Cu°/Cu+ couple (DPV), the current peak is sensitively affected by glyphosate concentration. A strong adsorptive effect between 6 and 30 μM of analyte leads to a linear decre