The surface of graphene was decorated with nickel/nickel oxide/nickel-boron particles to develop high-performance electrochemical sensors. The nanohybrid structures were prepared via a one-step reduction method under an oxygen-rich atmosphere to obtain an oxide phase besides metallic nickel nanoparticles. In addition, the use of NaBH4 as the reducing agent enabled simultaneous formation of Ni-B species on the graphene surface. XRD, XPS, TEM, Raman, and TGA analyses were implemented to characterize the samples. The XRD and XPS results revealed the presence of Ni/NiO/Ni-B on the surface of graphene. The electroanalytical performance of the nanocomposite was investigated against acetaminophen, which is an extensively exploited antipyretic and analgesic drug. The analytical performance results showed that the Ni/NiO/Ni-B/Gr-based sensors had a very wide working window between 10 μM and 2500 μM (y (μA) = 10.706x (mM) + 0.3151 (R2 = 0.9993)). The excellent storage stability, selectivity, and recovery results along with the high analytical performance make the novel Ni/NiO/Ni-B/Gr hybrid systems promising materials for the development of novel sensor platforms.