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 developed a simple method to prepare nitroso-uracil functionalized graphene oxide (GO-NO-Ur) and nitroso-uracil functionalized reduced graphene oxide (rGO-NO-Ur) for the detection and determination of heavy metals. The synthesized materials were characterized by FTIR, XRD, TGA, SEM, TEM, EDX, and UV-Vis spectroscopy. We have studied the application of both GO-NO-Ur and rGO-NO-Ur for the detection of various metallic ions such as Ag(I), Fe(III) and Cr (VI). The LOD and LOQ value of Ag(I) were found to be 4.6 mg/L and 14.1 mg/L at lmax 257 nm, respectively. Whereas, the LOD values were observed 4.6 mg/L and 4.8 mg/L at lmax 269 nm and lmax 375 nm, respectively. The LOQ values of Cr(VI) were found to be 14.1 mg/L and 14.12 mg/L at max 269 nm and 375 nm, respectively. This method is very effective for the selective detection of Cr (VI) and Ag (I) present in aqueous environments and may be used for a variety of biological as well as environmental samples.