In our recent work [Electrochim. Acta 240 (2017) 388-398], we examined the adsorption energy of glucose on graphene via Ni nanoparticles. In the present study, we have responded to comments to clarify the intricacies of dispersion effect and adsorption energies in our previous work. We have explored the performance and accuracy of some established and promising theoretical schemes, namely, the two-, three- (DFT-D2/3), and many-body (MBD@rSC) dispersion approaches, to account properly for the dispersive force contributions, which were not previously included in the system. Incorporating dispersive forces drastically increased the adsorption energy of glucose (E-ads), where different active sites were obtained. The calculated energies were in the order E-ads((DFT-D2)) < E-ads((DFT-D3)) < E-ads((MBD@rSC)). However, because the accuracy of the preferred MBD@rSC method is closely related to the mesh-grid, it is too early to conclude which theoretical approach gives the most satisfactory results. The dependence of the glucose active site and adsorption energy was sensitive to the used theoretical approximation. Therefore, the accuracy of the selected theoretical method should be always tested or compared with the experimental data. (C) 2019 Elsevier Ltd. All rights reserved.