A nanocomposition for modulating cell behaviors and methods of uses thereof. The nanocomposition comprises a nanostructure comprising at least one nanoparticle and at least one cell-modulating agent operably linked to the nanostructure. The cell-modulating agent can interact with a molecule on the surface of a cell, wherein the interaction between the cell-modulating agent and the molecule modulates a behavior of the cell, or purify and concentrate a cell population.