The properties of II-VI semiconductors capped with biocompatible organic molecules are very sensitive to preparation conditions such as pH, temperature, molar concentration of the precursors, synthesis techniques, nucleation atmosphere etc. For the use of any type of nanostructures, the results should be reproducible and stable. It is very important from the industrial point of view that one should study the various parameters of the nanostructures with respect to time domain. To use nanomaterials effectively, surface passivation is required. So it is important to study various capping agents, their concentration effect & other synthesizing parameters on optical and morphological behavior of ZnO nanostructures. Furthermore the fabricated nanomaterials can be used for various smart applications in optoelectronic industry and biomedical fields. As organic capping is best suited for passivation as well as functionalization of surface for biomedical applications, present work emphasizes the use of biocompatible organic capping agents to synthesize core-shell ZnO nanostructures using chemical routes & to explore their applications for next era smart applications.