  Functionalized nanoparticles (NPs) are complex objects present in a variety
of systems ranging from synthetic grafted nanoparticles to viruses. The
morphology and number of the decorating groups can vary widely between systems.
Thus, the modelling of functionalized NPs typically considers simplified
spherical objects as a first-order approximation. At the nanoscale label,
complex hydrodynamic interactions are expected to emerge as the morphological
features of the particles change, and they can be further amplified when the
NPs are confined or near walls. Direct estimation of these variations can be
inferred via diffusion coefficients of the NPs. However, the evaluation of the
coefficients requires an improved representation of the NPs morphology to
reproduce important features hidden by simplified spherical models. Here, we
characterize the passive transport of free and confined functionalized
nanoparticles using the Rigid Multi-Blob (RMB) method. The main advantage of
RMB is its versatility to approximate the mobility of complex structures at the
nanoscale with significant accuracy and reduced computational cost. In
particular, we investigate the effect of functional groups distribution, size
and morphology over nanoparticle translational and rotational diffusion. We
identify that the presence of functional groups significantly affects the
rotational diffusion of the nanoparticles, moreover, the morphology of the
groups and number induce characteristic mobility reduction compared to
non-functionalized nanoparticles. Confined NPs also evidenced important
alterations in their diffusivity, with distinctive signatures in the
off-diagonal contributions of the rotational diffusion. These results can be
exploited in various applications, including biomedical, polymer nanocomposite
fabrication, drug delivery, and imaging
