High-performance electrochemical amperometric sensors for the sensitive determination of phenyl urea herbicides diuron and fenuron

We have described the fabrication of high-performance amperometric sensors derived from graphene oxide-multiwalled carbon nanotube (GO-MWCNT) composite for the sensitive determination of diuron and fenuron. GO-MWCNT composite was prepared by simple solution-based approach, and its formation was confirmed by scanning electron microscopy, transmission electron microscopy and UV-visible spectroscopy methods. GO-MWCNT film-modified glassy carbon electrode exhibited excellent electrocatalytic performance in the oxidation of diuron and fenuron in terms of less overpotential and highly enhanced peak currents. GO-MWCNTs have presented significantly improved electrocatalytic performance than dimethylformamide-dispersed MWCNTs. GO-MWCNT-based amperometric sensor has been fabricated which detects diuron in wide linear range between 9 mu M and 0.38 mM with high sensitivity of 0.645 mu A mu M-1 cm(-2). The amperometric sensor also detects fenuron in broad linear range between 0.9 and 47 mu M with sensitivity of 1.20 mu A mu M-1 cm(-2). Moreover, the sensor offers appreciable repeatability, reproducibility, and stability results. Practical feasibility of the prepared amperometric sensor has been assessed in various water samples collected from agricultural areas.