Here is an insight into the effects of interaction of ZnO nanoparticles and the various cellular level changes that are brought about by the help of Raman spectroscopy on individual Escherichia coli cells. Raman vibrational signatures show variation in peak intensities of some of the cellular components of E coli cells with increase in nanoparticles concentration. This can be attributed to the cellular and molecular changes associated with bacterial cell growth, as the cells proceed from lag phase to stationary phase, which indicates that ZnO interferences with bacterial growth. Growth kinetics studies show mitigation in growth and colony forming units (CFU) counts. Changes in cellular morphology as investigated by atomic force microscopy and scanning electron microscopy, show destruction and even rupture of cell wall at higher ZnO concentration. This study pertains to any alterations brought about at the cellular level, which may be extended to other nanomaterials in the environment and the effect on human cells as well.