Sensitive determination of trace 4-nitrophenol in water based on thio-β-cyclodextrin functionalized graphene/copper nanospheres

A variety of nitro aromatic compounds in natural water have become the serious pollution problem which attracted extensive attention in the field of environmental protection. Herein, a new nanohybrid was successfully prepared by facile chemical deposition of Cu nanospheres (CuNSs) on SH-β-CD functionalized reduced graphene oxide (SH-β-CD-RGO). The as synthesized SH-β-CD-RGO/CuNSs nanocomposite was characterized by UV-vis spectroscopy, Fourier transform Infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and cyclic voltammetry (CV). The new material possesses the advantages of RGO (large surface area and high conductivity), SH-β-CD (high supramolecular recognition and enriching ability) and CuNSs (large surface area and electrocatalysis) and exhibits enhanced electrochemical properties for 4-nitrophenol (4-NP) reduction. On this basis, a rapid and sensitive electrochemical method for the determination of trace 4-NP in water was established, which benefits from the synergetic effect of RGO, SH-β-CD and CuNSs. The constructed electrochemical 4-NP sensor based on SH-β-CD-RGO/CuNSs demonstrates speediness, good sensitivity, wide linear range (0.05-25 μM and 25-100 μM) and low limit of detection (20 nM). Furthermore, it has acceptable selectivity and feasibility for real water sample analysis. The proposed method is not only simple, practical and cost-effective, but also open up a new possibility for rapid field tests of trace amounts of 4-NP in environmental water samples.