RESUMO
While helix has elegant biomimetic structures and functionalities, it still remains a big question how the nanoscale helicity evolved from the molecular chiral building blocks across length scales. Herein, macrocyclic triangles composed of achiral edges and chiral vertices were rationally designed, in which the planar chirality emerged due to the restriction of edge rotation by intermolecular stackings and led to a unique chiral self-assembly. In contrast to the solution systems where the chiroptical property is exclusively dominated by the point chiral vertices, the emerged planar chirality was found to control the chiral self-assembly, resulting the nanotwist with the handedness determined by the planar chirality. Our work unveiled the self-assembly behaviors of macrocyclic conformers for the first time and provided a deep understanding on the macrocyclic chirality evolution including the excited-state chirality.
RESUMO
Microbial infections have become a great threat to human health and one of the main risks arises from direct contact with the surfaces contaminated by pathogenic microbes. Herein, a kind of hexagonal column interpenetrated spheres (HCISs) are fabricated by non-covalent assembly of plant gallic acid with quaternary ammonium surfactants. Different from one-time burst release of conventional antimicrobial agents, the HCIS acts like a "antimicrobial molecular bank" and releases the antimicrobial ingredients in a multistage way, leading to long-lasting antimicrobial performance. Taking advantage of strong hydrophobicity and adhesion, HCISs are applicable to various substrates and endowed with anti-water washing property, thus showing high in vitro antimicrobial efficiency (>99 %) even after being used for 10 cycles. Meanwhile, HCISs exhibit broad-spectrum antimicrobial activity against bacteria and fungi, and have good biocompatibility with mammalian cells. Such a low-cost and portable long-lasting antimicrobial agent meets the growing anti-infection demand in public spaces.