We describe the preparation of oil-in-water (o/w) colloidal particles with a polypyrrole (pPy) shell in which cyclodextrin has been incorporated at the oil-water interface via either physical adsorption or reaction with the pPy shell. The utility of these particles was assessed by the extraction of organic dyes from water. In all cases, we found that cyclodextrin incorporation significantly improved dye uptake, giving up to 78 ± 11% dye extraction in the case of a 100 ppm solution of 4-nitroaniline with a covalently incorporated cyclodextrin. We demonstrated the ability of our colloidal particles to extract nicotine-derived nitrosamine ketone (NNK), a potent carcinogen, from aqueous solution. By treating the solution containing 100 ppm NNK with our particles over 24 and 48 h, we found that NNK removal reached 65 ± 2 and 83 ± 1%, respectively. The uptake could be improved by re-treating a solution with additional freshly prepared particles, to achieve 95 ± 1% NNK extraction with a covalently incorporated cyclodextrin.
Keywords: colloidal particles; cyclodextrin; extraction; host−guest chemistry; nicotine-derived nitrosamine ketone; polypyrrole.