• Dar, Riyaz Ahmad
• Rezakazemi, Mashallah
• Karna, Shashi P.
• Srivastava, Ashwini Kumar
• Giri, Lily
• Shaikh, Ahamad M. H.
• Hassan, Israr Ul
• Ahmed, Waqar

Abstract

<jats:title>Abstract</jats:title><jats:p>Graphene: zinc oxide nanocomposite (GN:ZnO NC) platform was tried for the sensitive determination of para-nitrophenol (p-NP) through the electrochemical method. ZnO nanoparticles (NPs) were synthesized by the modified wet-chemical method where in potassium hydroxide and zinc nitrate were used as precursors and starch as a stabilizing agent. A green and facile approach was applied to synthesize GN:ZnO NC in which glucose was employed as a reductant to reduce graphene-oxide to graphene in the presence of ZnO NPs. The synthesized NC was characterized using scanning and high-resolution transmission electron microscopy, energy dispersive x-ray analysis, X-ray diffraction and Raman spectroscopic techniques to examine the crystal phase, crystallinity, morphology, chemical composition and phase structure. GN:ZnO NC layer deposited over the glassy carbon electrode (GCE) was initially probed for its electrochemical performance using the standard 1 mM K<jats:sub>3</jats:sub>[Fe(CN)<jats:sub>6</jats:sub>] model complex. GN:ZnO NC modified GCE was monitored based on p-NP concentration. An enhanced current response was observed in 0.1 M phosphate buffer of pH 6.8 for the determination of p-NP in a linear working range of 0.09 × 10<jats:sup>–6</jats:sup> to 21.80 × 10<jats:sup>–6</jats:sup> M with a lower detection limit of 8.8 × 10<jats:sup>–9</jats:sup> M employing square wave adsorptive stripping voltammetric technique at a deposition-potential and deposition-time of − 1.0 V and 300 s, respectively. This electrochemical sensor displayed very high specificity for p-NP with no observed interference from some other possible interfering substances such as 2, 4-di-NP, ortho-NP, and meta-NP. The developed strategy was useful for sensitive detection of p-NP quantity in canals/rivers and ground H<jats:sub>2</jats:sub>O samples with good recoveries.</jats:p>

Topics

• nanoparticle
• Deposition
• nanocomposite
• Carbon
• phase
• x-ray diffraction
• zinc
• chemical composition
• Potassium
• transmission electron microscopy
• crystallinity