Carbon dioxide (CO2)-responsive polymers have been gaining considerable interest because of their reactions with CO2, giving rise to gas-switchable properties, which can easily be reversed by mild heating or purging with inert gases. Herein, the synthesis of a series of side-chain amino acids (alanine, leucine, isoleucine, phenylalanine, tryptophan) appending poly(meth) acrylates carrying primary amine (-NH2) groups via reversible addition-fragmentation chain transfer (RAFT) polymerization method was reported. It was found that alanine, leucine, isoleucine containing polymers displayed solubility-insolubility transition behavior and their associated property changes (solution transmittance, electrical conductivity, pH, zeta potential, and hydrodynamic diameter) in water upon alternate bubbling of CO2/N-2 at room temperature. Among the three CO2-sensitive polymers only leucine based macromolecule was further chain extended with a thermoresponsive motif, di(ethylene glycol) methyl ether methacrylate (DEGMMA), via RAFT polymerization. CO2-tunable lower critical solution temperature and self-assembling behavior of the diblock copolymer was carefully examined by UV-vis, H-1 NMR spectroscopy, dynamic light scattering (DLS), and field emission-scanning electron microscopy (FE-SEM) to establish dual thermo and gas-tunable flip-flop micellizaion from the assynthesized block copolymer. Formation of polyammonium methacrylate bearing bicarbonate as counter anion is responsible for pendant primary amine containing polymer induced CO2-responsiveness. (C) 2016 Wiley Periodicals, Inc.