Fluorescent Cdots(N)-Silica composites: Direct synthesis and application as electrochemical sensor of fenitrothion pesticide

Abstract

In this work, we reported the synthesis of fluorescent and electrochemically active Cdots(N)-Silica composites by very simple route based on classical sol–gel techniques. The microporous composites exhibited luminescence associated with Cdots emitting centers, and were characterized by Ultraviolet–visible, photoluminescence, Fourier Transform InfraRed, Raman, X-Ray Diffraction, Scanning Electron Microscopy, Adsorption/desorption N2, Atomic force microscopy and electrochemical techniques. They were applied as electrochemical sensor, by the glassy carbon surface modification with Cdots(N)-Silica films, showing a consistent electrocatalytic performance for the analysis of fenitrothion pesticide, as determined by differential pulse voltammetry. The GCE/Cdots(N)-Silica composite sensors exhibited a detection limit of 1.05 × 10-9 mol L-1 associated with a high selectivity, and have been successfully applied for the determination of the fenitrothion pesticide in orange juice samples.