▎ 摘　　要

Heavy metal pollution is a very serious issue for living beings. The estimation of heavy metals is an expensive and complex process. Herein, we have reported a simple method to prepare a high-performance graphene nanocomposite; the nitroso-uracil functionalized graphene oxide (GO-NO-Ur) and nitroso-uracil functionalized reduced graphene oxide (rGO-NO-Ur). The physicochemical characterization of synthesized materials was done using FTIR, XRD, TGA, SEM, EDX, TEM and UV-vis spectroscopy. The rGO-NO-Ur has better physicochemical properties compared to GO-NO-Ur. Finally, the resulted rGO-NO-Ur was used for the detection of heavy metals, which is our prime objective of the present work. Among the number of metals, Cr (VI) is very selective and sensitive towards the rGO-NO-Ur, shown a specific absorption band at 350 nm. The LOD and LOQ values of Cr (VI) are at 350 nm, 5.19 nM, and 15.73 nM, respectively. Whereas, the LOD and LOQ values of Cr (VI) are at 257 nm, 6.79 nM, and 20.58 nM, respectively. This method is very effective for selective detection of Cr (VI), present in an aqueous medium and can be used for a variety of biological as well as environmental samples.