In order to enhance the utilization of nanomaterial in biological systems, it is very important to understand the influence they impart on cellular health and function. Nanomaterials present a research challenge as very little is known about how they behave in relation to micro-organisms, particularly at the cellular and molecular levels. Most of the nanomaterials reported earlier have demonstrated to be efficient antimicrobial agents against virus, bacteria or fungus. There are scarce research reports on the growth-promoting role of nanomaterials especially with respect to microbes. Recent findings, however, have challenged this concept of antimicrobial activity of nanoparticles.