Controlled synthesis of reduced graphene oxide supported silver nanoparticles for selective and sensitive electrochemical detection of 4-nitrophenol

• Published in: Electrochimica acta 2016-02, Vol.192, p.392-399
• Main Authors: Ikhsan, Nurul Izrini, Rameshkumar, Perumal, Huang, Nay Ming
• Format: Article
• Language: English
• Subjects: 4-Nitrophenol; Electrochemical sensor; Electrodes; Graphene; Modified electrode; Nanocomposites; Nanoparticles; Nanostructure; Reaction time; Reduced graphene oxide; Reduction; Silver; Silver nanoparticles
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2016.02.005

Controlled synthesis of reduced graphene oxide-silver (rGO-Ag) nanocomposite using modified Tollens’ test and its application towards the electrochemical detection of 4-nitrophenol (4-NP) is reported. The rGO-Ag (15h) nanocomposite modified GC electrode showed a good sensitivity in square wave voltammetry with a detection limit of 1.2nM towards the electrocatalytic reduction of 4-NP. The nanocomposite was stable and selective for 4-NP detection in the presence of interferent molecules. The present nanocomposite assay was successfully used for the determination of 4-NP in real water samples. [Display omitted] •rGO-Ag nanocomposite was prepared using modified Tollens test.•Reaction time dependent formation of Ag nanoparticles was analyzed.•The nanocomposite was used for the electrochemical detection of 4-nitrophenol.•The limit of detection was found to be 1.2nM for 4-NP detection.•It was applied for the determination of 4-NP in real water samples. An electrochemical sensing platform made of a reduced graphene oxide-silver (rGO-Ag) nanocomposite was developed for the detection of 4-nitrophenol. The synthesis of the nanocomposite was monitored at different reaction times (2h, 6h, 10h and 15h) in modified Tollens’ test and characterized using UV-visible absorption spectrum, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy analyses. Completely spherical Ag nanoparticles (NPs) were found at a reaction time of 15h with an average particle size of 16nm. The nanocomposites prepared with different reaction times were used for the electrocatalytic reduction of 4-NP, and the rGO-Ag (15h) nanocomposite-modified glassy carbon (GC) electrode displayed a higher faradaic current at an overpotential of −0.5V toward 4-NP reduction. The rGO-Ag (15h) nanocomposite-modified electrode was used for the square wave voltammetric (SWV) detection of 4-NP in a 0.1M phosphate buffer (pH 7.2), and it showed a good sensitivity toward 4-NP detection even for a nanomolar concentration. The nanocomposite exhibited multi-linear ranges and 4-NP detection limit was found to be 1.2nM. The present sensor was stable and selective to 4-NP in the presence of its structural analogues such as 2-nitrophenol (2-NP), 2-aminophenol (2-AP), 3-aminophenol (3-AP), 4-aminophenol (4-AP), and 2,4-dichlorophenol (2,4-DCP). The rGO-Ag nanocomposite could be successfully applied for the determination of 4-NP in real water samples, and good recoveries were found.