Bismuth selenise has been considered as one of the most prominent topological insulators wherein the surface states plays specific roles for certain applications such as quantum Hall effect, quantum computing and polarizablity sensitive photodetecting. Hereby we investigate the electronic structure and surface states , the polarity at the surface based on the charge density profiles at surface and the phonon-electron interactions in order to study the photodetecting applications and the polarizability sensing of bismuth selenide nanostructures. The results pave the routes towards the optimization of the polarizablity/sensors based on novel topological insulator materials in general and worth further investigation.