Functionalised multi-walled carbon nanotubes-modified electrode for sensitive determination of Diuron in seawater samples

This work was focused in to develop an electroanalytical method based on a direct modification of a glassy carbon electrode (GCE) by the deposition of successive aliquots of diluted dispersions of functionalised carbon nanotubes (MWCNT-COOH) in ethanol (0.1 mg.mL(-1)) aiming the determination of Diuron into seawater samples, a common antifouling substance, using differential pulse voltammetry as electroanalytical technique. The GCE/MWCNT-COOH showed a sensitivity of 2.20 mu A/mu mol L-1 about 10 times higher than the unmodified counterpart (GCE) which showed a sensitivity of 0.192 mu A/mu mol L-1. The limits of detection and quantificationwere 6.88 x 10(-8) and 2.29 x 10(-7) mol L-1 for GCE/MWCNT-COOH while for GCE were 7.87 x 10(-7) and 2.62 x 10(-6) mol L-1, respectively. The applicability was evaluated with spiked detectable amounts of Diuron into seawater samples. The recovery results were between 76% and 119%.