Functionality, one of the key attributes of atom transfer radical polymerization (ATRP), was utilized for the synthesis of well-controlled polymers functionalized with biotin, pyrene, and peptides. Hydroxy-functionalized poly(oligo(ethylene oxide) monomethyl ether methacrylate) (HO-POEOMA) was prepared by AGET ATRP of OEOMA initiated by 2-hydroxyethyl 2-bromoisobutyrate in water or in inverse miniemulsion of water/cyclohexane at ambient temperature. HO-POEOMA was then further functionalized with biotin, pyrene, and GRGDS peptide. In addition, ATRP and click chemistry offered an efficient route for the synthesis of telechelic di-biotin polymers. These general methods can be applied to the formation of different functional materials conjugated with proteins, dyes, nucleic acids, and drugs.