Molecularly imprinted polymers have been studied for a long time and have found useful applications in many fields. In most cases, small organic molecules are used as templates to synthesize imprinted polymers. In contrast to low molecular weight targets, large biological molecules and cells are more challenging to use as templates to synthesize cell-recognizing materials. This chapter presents an interfacial imprinting method to synthesize bacteria-recognizing polymer beads using Pickering emulsion polymerization. The tendency of bacteria to reside between two immiscible liquids is utilized to create surface-imprinted binding sites on cross-linked polymer microspheres.