This dissertation presents theoretical and experimental studies on the optical and transport properties of selected nano-objects. The theoretical part of this work is particularly devoted to the study of the optical spectra of quasi-1D gold nanoparticle assemblies, single gold nanorod and its chiral dimer. The theoretical method is based on the analytical and numerical solutions to the classical Maxwell's equations. Specifically, quasi-1D gold nanoparticle assemblies of equal width comprising nanoparticles with different sizes, the onset of the infinite chain limit and its associated energy are governed by the number of repeat units and not the overall length of the polymer. Chiral, twisted, self-assembled gold nanorod dimers were modelled by the finite-difference time-domain method. It is demonsrated through extensive simulations that the lineshape of the scattering circular dichroism spectra of twisted gold nanorod dimers is tuned through two major ways of symmetry breakings: size mismatch and twistness. Finally, using single-molecule fluorescence microscopy, the transport properties of an interesting surface-rolling molecule, \textit{nanocar}, is characterized by means of its 2D diffusion coefficient and fraction of moving, which are in good agreement with a 2D surface diffusion model. The findings presented in this thesis bring deeper and more sophisticated understanding to the underlying mechanisms of nanoscience.