The 5th International Conference of Theoretical and Applied Nanoscience and Nanotechnology (TANN’21) aims to become the leading annual conference in fields related to nanoscience and nanotechnology. The goal of TANN’21 is to gather scholars from all over the world to present advances in the fields of nanoscience and nanotechnology and to foster an environment conducive to exchanging ideas and information. This conference will also provide an ideal environment to develop new collaborations and meet experts on the fundamentals, applications, and products of the mentioned fields.