Genistein (5,7,4′-trihydroxyisoflavone) is an isoflavone abundantly found in soy and other legumes and acts as a selective estrogen receptor modulator (SERM). When testing for similar abilities among other flavonoids, it has been found to be a strong topoisomerase inhibitor. Similar to some high-dose chemotherapy drugs, it was strongly toxic to normal cells. In this study, the adsorption of genistein on the surface of exclusive graphene and Ni, Ti, Cr, and Se-doped graphene was theoretically evaluated by means of density functional theory calculation. Initially, we varied the position of genistein from the surface of pristine and decorated graphene by changing the distances between (1-5 Å) and gained the Ead and Egap for each situation. Our calculation indicated that adsorption energies (Ead) of pristine genistein to graphene with Ni decorated graphene, Ti-     decorated graphene, and Cr-decorated graphene and Se-decorated graphene are: 954.984, 318.168, 797.480, 946.725, 958.154 kcal/mole, respectively, and the calculated values of adsorption energy in the equilibrium distance (de=3.918OA.) of genistein to Ni-decorated graphene reveal that apparently genistein- Ni-decorated graphene as the most energetically favorable position was correctly selected in comparison with other atom     -decorated graphene. In consequence, we explain the density of states (Doss) and frontier molecular orbitals HOMO and LUMO for Ni-decorated graphene and complexes with genistein; therefore, data confirmed that a positive charge of Ni-decorated graphene for nucleophile molecules could be achieved.

Genistein is an isoflavone that is used as a drug to stop various types of cancer cells, such as breast and prostate cancer. This study aimed to perform molecular simulation of the adsorption process of genistein molecule on pure graphene and genistein on graphene doped with metal atoms (Ni, Ti, Se, and Cr) to increase the adsorption efficiency of the genistein-graphene molecule.Material & Methods: In this study, a graphene plate (dimensions: 4 × 4) was placed next to the genistein molecule at a distance of 1 to 5 angstroms, using HyperChem Professional software (version 8.0.10). The density functional theory (DFT) was used to simulate the adsorption of Genistein-graphene, and the Gaussian software (version 09), hybrid method (B3LYP), and the 6-31G base set were used to optimally design the molecular structure. Findings: Based on the obtained results, the adsorption energy of genisteingraphene doped with metal atoms Ni, Se, Ti, and Cr was determined at 318.154, 954.080, 972.745, and 1236.149 kcal/mole, respectively, and the energy gap of genistein-graphene doped with Ni, Ti, Se, and Cr was estimated to be 85. 422, 92.476, 102.396, and 94.694 kcal/mol, respectively. Discussion & Conclusion:The results of this study show that the presence of graphene-doped Ni atoms increases the electron charge density. The energy gap of genistein-graphene doped with Ni atoms indicates reactivity and high electron charge density of this compound and can be used as a suitable option to increase the uptake efficiency of the genistein drug molecule.