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Abstract Halorhodopsin, a light-driven chloride pump, utilizes photonic energy to drive chloride ions across biological membranes, regulating the ion balance and conveying biological information. In the light-driven chloride pump process, the chloride-binding chromophore (protonated Schiff base) is crucial, able to form the active center by absorbing light and triggering the transport cycle. Inspired by halorhodopsin, we demonstrate an artificial light-driven chloride pump using a helical porphyrin channel array with excellent photoactivity and specific chloride selectivity. The helical porphyrin channels are formed by a porphyrin-core star block copolymer, and the defects along the channels can be effectively repaired by doping a small number of porphyrins. The well-repaired porphyrin channel exhibits the light-driven Cl− migration against a 3-fold concentration gradient, showing the ion pumping behavior. The bio-inspired artificial light-driven chloride pump provides a prospect for designing bioinspired responsive ion channel systems and high-performance optogenetics.

Oxygen-containing functional groups play crucial roles in graphene oxide due to their enhanced processability, stability, and functionalization. However, achieving precise control over the oxidation degrees of graphene oxide through a straightforward and effective method remains a significant challenge. Herein, we report a two-step electrochemical approach encompassing pre-intercalation and post-exfoliation/oxidation, enabling the mass exfoliation of graphene oxide with customizable oxidation levels. Initially, the pre-intercalation of concentrated sulfuric acid into graphite foil promotes uniform expansion, transforming it into a quasi-monolayer graphene structure. Subsequently, post-exfoliation in reductive/oxidative electrolytes triggers the simultaneous detachment and oxidation process, resulting in well-dispersed graphene nanosheets with quantified oxidation levels on a timescale of minutes. Comprehensive characterization studies confirm the varied oxidation levels of the exfoliated graphene oxide, spanning conventional oxidation degrees obtained via Staudenmaier's, Hofmann's, and Hummers' methods. Furthermore, we evaluate the scalability of this method and the solution processability of exfoliated graphene nanosheets, demonstrating the continuous production of graphene oxide at the kilogram scale and the fabrication of meter-length nanocomposite films with exceptional mechanical properties. [ABSTRACT FROM AUTHOR]