A glassy carbon electrode was functionalized by MoO2 nanoparticle-decorated multiwalled carbon nanotubes (MWCNTs) and examined as a working electrode in oxyfluorfen (OXY) detection by differential pulse stripping voltammetry (DPSV). Measurement parameters were as follows: initial potential - 0.1 V, end potential + 0.5 V, accumulation potential - 0.15 V, accumulation time 80 s, and scan rate 50 mV s-1. A stripping potential of + 0.315 V vs. Ag/AgCl was employed. The pPesticide oxyfluorfen was determined in model samples by DPSV with good reproducibility (RSD <2.4%) in the concentration range 2.5 to 34.5 ng mL-1, with r = 0.99 and a limit of detection of 1.5 ng mL-1. These results are in the same range as those of HPLC/DAD, which is used as the comparative method. Recovery for OXY determination in a real river water sample was 102%. Analyses in Briton-Robinson buffer has shown to be pH dependent with the best response at pH 6.0. Structural characterization of MoO2-MWCNT by Raman spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray crystallography revealed a preserved MWCNT structure decorated with firmly attached clusters of MoO2 nanoparticles. Graphical abstract Glassy carbon electrode functionalized by MoO2 nanoparticle-decorated multiwalled carbon nanotubes is used as a working electrode in the voltammetric determination of pesticide oxyfluorfen in water.
Keywords: Carbon nanotube; Differential pulse stripping voltammetry; Glassy carbon electrode; Pesticide determination; Sensor.