Binder Free Modification of Glassy Carbon Electrode by Employing Reduced Graphene Oxide/ZnO Composite for Voltammetric Determination of Certain Nitroaromatics

Abstract

Reduced Graphene oxide/ZnO nanoflowers (rGO/ZnO-NFs) composite has been synthesized in-situ using asymmetric Zn complex (1) as a single-source molecular precursor (SSMP) with GO at 150 °C. The rGO/ZnO-NFs composite was characterized by PXRD, UV-vis, SEM, EDX mapping, TEM and SAED pattern to confirm its purity and morphology. The rGO/ZnO-NFs composite shows uniform distribution of nanoflowers on graphene sheets. The modified glassy carbon electrode (GCE) was fabricated by drop wise layering of the rGO/ZnO-NFs composite at the surface of the GCE without using binder. The binder free modified electrode (GCE-rGO/ZnO) was explored for detection of nitroaromatics such as p-nitro-phenol (p-NP), 2,4-dinitrophenol (2,4-DNP), 2,4-dinitrotoluene (2,4-DNT) and 2,4,6-trinitrophenol (2,4,6-TNP). The fabricated sensor showed remarkable response for the both toxicants and explosives. The LOD, sensitivity and linear range for the studied toxicants and explosives were found to be in a good range: p-NP=0.93 μM, 240 μA mM−1 cm−2 and 0.2–0.9 mM; 2,4-DNP=6.2 μM, 203 μA mM−1 cm−2 and 0.1–0.9 mM; 2,4-DNT=10 μM, 371 μA mM−1 cm−2 and 0.2–0.9 mM; 2,4,6-TNP=16 μM, 514 μA mM−1 cm−2 and 0.2–0.9 mM, respectively. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim