Graphitic carbon nitride/graphene oxide(g-CN/GO) nanocomposites covalently linked with ferrocene containing dendrimer for ultrasensitive detection of pesticide.

We report herein the design of a novel electrochemical sensing strategy for sensitive detection of pesticide based on graphitic carbon nitride (g-CN)/graphene oxide(GO) nanocomposite covalently bound to a ferrocene containing dendrimer(Fc-TED). The g-CN with sufficient N atoms for providing lone pairs of electrons to an electron acceptor so as to enhance the adsorption towards organic molecules. The Fc-TED dendrimers with the native redox signaling center (Fe/Fe) can increase the electron transition of g-CN from valence to conduction band. While GO can accelerate the electron transfer from g-CN surface and Fc-TED to glassy carbon electrode(GCE), which would amplify the electrochemical signal of g-CN/GO/Fc-TED/GCE sensor and then improve the sensing performance. It is found that the fabricated electrode demonstrated an admirable electrochemical sensing performance towards metolcarb in terms of low detection limit (8.3 nM), wide concentration range (0.045-213 μM) and rapid response time (2s). The proposed sensor can selectively detect the metolcarb and easily discriminated metolcarb from the possible interfering species. The practical applicability of the sensor was successfully evaluated in real vegetable sample and achieved satisfactory recoveries with good precision and accuracy.