Novel types of dual-functional surface-attached polymer brushes were developed by interface-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization of 6-azidohexylmethacrylate using the surface-immobilized RAFT agent and the free initiator. The interface-mediated RAFT polymerization produced silicon substrate coated with dual-functional (azido groups from monomer and carboxylic acid groups from RAFT agent) poly(6-azidohexylmethacrylate) [poly (AHMA)] with a grafting density as high as 0.59 chains/nm(2). Dual-functional polymer brushes can represent an attractive chemical platform to deliberately introduce other molecular units at specific sites. The azido groups of the poly(AHMA) brushes can be modified with alkyl groups via click reaction, known for their DNA hybridization, while the carboxylic acid end groups can be reacted with amine groups via amide reaction, known for their antifouling properties. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1696-1706