"Currently, protein dynamics are well established using semiconductor nanocrystals conjugation. Low semiconductor crystalline variance between InP core and ZnS shell since they have same zinc blend crystal structure further reduces the possibility of surface trap states and enhances the PL quantum efficiency. The current thesis emphasizes on the detailed investigation of the interaction between biocompatible and greener (toxic free) PEG-InP/ZnS QDs with most abundant globular proteins HSA and BSA using various multi-spectroscopic tools. In addition to it, the present work presents comprehensive study of resonance energy transfer between these QDs and highly fluorescent organic dyes CV and Rh-6G in order to design less carcinogenic FRET pairs for further in vivo biomedical applications".