The facile and controlled fabrication of homogeneously grafted cationic polymers on carbon nanotubes (CNTs) remains poorly investigated, which further hinders the understanding of interactions between functionalized CNTs with different nucleic acids and the rational design of appropriate gene delivery vehicles. Herein, we describe the controlled grafting of cationic poly­(2-dimethylaminoethylmethacrylate) brushes on CNTs via surface-initiated atom transfer radical polymerization integrated with mussel-inspired polydopamine chemistry. The binding of nucleic acids with different brush-CNT hybrids discloses the highly architectural-dependent behavior with dense short brush-coated CNTs displaying the highest binding among all the other hybrids, namely, dense long, sparse long, and sparse short brush-coated CNTs. Additionally, different chemistries of the brush coatings were shown to influence the biocompatibility, cellular uptake, and silencing efficiency in vitro. This platform provides great flexibility for the design of polymer brush-CNT hybrids with precise control over their structure–activity relationship for the rational design of nucleic acid delivery systems.

Supercapacitors (SCs) have attracted great attention as renewable energy storage devices due to their high power densities and cost effectiveness. In this work, a one-step method is reported to fabricate the laser scribed SC using laser reduced Polyimide (LRPI) electrodes as a substrate. An Iono-gel polymer electrolyte based on polyvinyl alcohol, potassium hydroxide and 1-Butyl-3-methyl imidazolium Bromide ([Bmim]Br) was utilized because of its wider voltage window, good ionic conductivity and better adhesion with electrode material. The assembled device exhibited an excellent specific capacitance of 2.19 mFcm −2 at a maximum current density of 0.263 mAcm −2. The energy density is measured to be 1.21 µWhcm −2 , which is much higher than a usual capacitor. Given these electrochemical properties, a cost-effective one-step method and scalable approach provides a strategy to fabricate lightweight, stretchable and flexible supercapacitors for future microscale energy storage devices i.e., flexible displays, electrical sensors and wearable electronics.