Graphene hybrid nanostructures based screen-printed sensor employed in the glyphosate electrocatalytic determination in the real sample

This work describes the synthesis characterization and application of innovative CuONPs/GO/CDot(N) nano- structures obtained by direct reaction between graphene oxide, nitrogen-doped carbon quantum dots (CDot(N)), and copper (II) nitrate. The hybrid nanostructures were characterized by spectroscopies methods such as Raman, ultraviolet-visible (UV-Vis), and X-ray photoelectron spectroscopies (XPS), X-ray diffraction (XRD), High- resolution transmission electron microscopy (HR-TEM), and electrochemical techniques. A sensitive electrochemical sensor to determine glyphosate in the real sample has been constructed by a printed carbon electrode modified with CuONPs/GO/CDot(N) nanostructures. Determination of the pesticide glyphosate (glyph) has been performed in phosphate buffer solution (PBS) at pH 5.5 and in real water samples by differential pulse voltammetry technique (DPV). The printed carbon electrode modified with CuONPs/GO/CDot(N) nanostructures presented a detection limit of 1.97 nmol.L-1 (0.3 mu g.L-1). The modified, printed carbon electrode determined glyphosate in real samples, with recovery ranging from 95.2 % to 114%. Other pesticides didn't present significant interference in the glyphosate determination.