Six‐Pointed Star Chiral Cobalt Superstructures with Strong Antibacterial Activity

Abstract Chiral inorganic nanomaterials have shown promise as a potential means of combating bacteria due to their high levels of biocompatibility, easy surface modification, and excellent optical properties. In this study, a diverse range of chiral hierarchical nanomaterials are prepared from Co2+ and L/D‐Tartaric acid (Tar) ligands. By combining the ligands in different ratios, chiral Co superstructures (Co SS) are obtained with different morphologies, including chiral nanoflowers, chiral nanohanamaki, a chiral six‐pointed star, a chiral fan shape, and a chiral fusiform shape. It is found that the chiral six‐pointed star structures exhibit chiroptical activity across a broad range of wavelengths from 300 to 1300 nm and that the g‐factor is as high as 0.033 with superparamagnetic properties. Under the action of electromagnetic fields, the chiral six‐pointed star Co SS shows excellent killing ability against Gram‐positive Staphylococcus aureus (ATCC 25923). Compared to L‐Co SS, D‐Co SS shows stronger levels of antibacterial ability. It is found that the levels of reactive oxygen species generated by D‐Co SS are 1.59‐fold higher than L‐Co SS which is attributed to chiral‐induced spin selectivity effects. These findings are of significance for the further development of chiral materials with antibacterial properties.