Physicochemical antibacterial mechanisms of rose-thorn-inspired micro-nano Cu conical coatings

The rising prevalence of bacterial antibiotic resistance threatens human health and public safety, posing a critical challenge to conventional antimicrobial strategies. Inspired by rose thorn architecture, this study employs Janus Green B (JGB) as a crystallization modifier in a CuSO 4 electroplating bath to fabricate a micro/nano-structured biomimetic JGB-Cu coating on aluminum alloy surfaces. The coating consists of submicron pyramid-shaped Cu cones with a specific surface area of ~ 3.07. Compared with polished Cu and traditional electroplated Cu coatings, the JGB-Cu coating exhibits substantially enhanced antibacterial activity, inhibiting > 90% of Escherichia coli ( E. coli ) within 30 min and achieving complete sterilization within 40 min. Soft X-ray analysis confirms that rapid Cu ion release induces E. coli cell deformation and disruption. Additionally, the conical structure exerts a “trapping” effect that causes cell plasmolysis and death via localized stress, a synergistic physico-chemical mechanism that effectively inactivates surface-adhered bacteria. Furthermore, the JGB-Cu coating demonstrates excellent liquid repellency (water contact angle > 160°), along with superhydrophobic and anti-adhesive properties. This biomimetic coating provides great potential for applications in medical hygiene and public health protection.