Slippery Liquid-Infused Porous Surfaces Using Eucalyptus Oil-Loaded Bead-on-String Nanofibers for Antibacterial, Antifungal, and Antibiofilm Applications

Slippery liquid-infused porous surfaces (SLIPS) are emerging as promising antifouling potential surfaces. However, conventional fabrication requires multistep chemical processes and synthetic lubricants with risks of accumulation. Herein, a simplified, nature-inspired route to multifunctional SLIPS by electrospinning bead-on-string polysulfone nanofiber-coated surfaces (bPSU_NfCS) directly onto glass, followed by infusion with Eucalyptus globulus oil (EGO) as a natural lubricant, resulting in EGO-infused bPSU_NfCS-SLIPS (bPSU_NfCS-EGO/SLIPS), is presented. Bead-on-string morphology and nanofibrous architecture provide roughness and internal reservoirs that trap EGO, thereby eliminating the need for etching or salinization. With infusion, bPSU_NfCS-EGO/SLIPS undergoes a hydrophobic-to-slippery transition, with contact angle decreasing from 121° to 61° and sliding angle to 5°, enabling repellency toward diverse liquids. The surfaces exhibited remarkable antibacterial efficacy, achieving 100% inhibition against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6338), along with effective suppression of Candida albicans (ATCC 30028). Biofilm formation by Pseudomonas aeruginosa (ATCC 27853) decreased by >80%, while mineral fouling from CaCO 3 was strongly inhibited. Cytocompatibility with HEK293-T cells confirmed nontoxicity, with >85% viability and adhesion. These findings validate the dual functionality of SLIPS, with passive repellency via slipperiness and active bioactivity. This strategy offers a scalable, biocompatible, sustainable pathway to multifunctional SLIPS with broad-spectrum antifouling performance, applicable to marine, environmental, and healthcare technologies.