In this work, gelatin-poly（acrylic acid） （GEL-PAA） nanospheres with diameter of around 35 nm were prepared using a polymermonomer （gelatin-AA） pair reaction system. These nanospheres can self-assemble into nanorods in aqueous solution at 4 ℃. Based on the observation that the intermediate state of the formation of the nanorods and the facts that the self-assembly can only occur at relatively low temperature and the gelatin molecules on the outermost layer of the GEL-PAA nanospheres can be renatured to triple helix conformation, it can be rationally inferred that the hydrogen bonding and electrostatic interactions between the gelatin molecules with the triple helix structure induce the one-dimensional self-assembly of the nanospheres into nanorods.
