A new approach to stabilize carbon nanotubes (CNTs) in aqueous solution with a reduction-responsive water-soluble polymer is reported. The novel polymer synthesized by a controlled radical polymerization is functionalized with pendant pyrene groups capable of adhering to the surface of CNTs through - noncovalent interactions, and labeled with disulfide linkages to exhibit reduction-responsive cleavage. Upon the cleavage of junction disulfide linkages in a reducing environment, water-soluble polymers are shed, retaining clean CNT surfaces for electrochemical catalytic reactions.