In the framework of classical electrodynamics and T-matrix approach, we theoretically study the interaction of electromagnetic radiation with matter to understand the optical phenomena on nanometer scale. Motivated by the rapid advance of nanoscience and nanotechnology, our research work explores the far-field behaviour of scattered light as well as the nature of optical near-fields. Particular interest is placed on the opto-mechanical properties induced by the interaction radiation-matter. In this context the theoretical bases underlying the optical manipulation technologies of natural and anthropogenic substances are studied in depth.