Research is focuesed on the preparation of antimicrobial surfaces using ATRP, one of living radical polymerizations. This strategy, involving covalent attachment of certain long, moderately hydrophobic polycations to material surfaces, has been proven to be very effective against a variety of pathogenic bacteria, both airborne and waterborne. Antimicrobial properties are being controlled by the chain length and counter ion of a water-soluble polymer polymerized by ATRP. This work continues along with a quest for creating material coatings with biosensor for bacteria and virus.