Surface curvature-directed in situ synthesis of ultrathin 2D MOFs on liquid metals for antibacterial applications

Abstract

Although promising as hybrid materials for catalysis, antibacterial treatments, and optoelectronics, conventional two-dimensional metal–organic frameworks (MOFs) sheets tend to pile into thick stacks to result in low surface areas. Here, we report a surface curvature-guided in situ synthesis strategy that employs gallium-based liquid metal particles (LMPs) as a confined reaction medium for fabricating ultrathin, large-area 2D MOF sheets. By implementing a pre-sonication step in decanol followed by centrifugation before synthesis in DMF, we create conditions that direct MOF growth outward from the curved LMP surfaces, resulting in MOF@LMP microflowers with ultrathin and uniform 2D MOF petals, which we call LOTUS (Liquid-metal Organized Thin Uniform Sheets). These microstructures exhibit exceptional antibacterial efficacy against multi-drug-resistant Gram-positive bacteria, with a minimum inhibitory concentration (MIC) of 2.4 µg mL⁻¹, operating through a synergistic mechanism that combines physical disruption, gallium ion release, and reactive oxygen species generation. Biocompatibility assessments further validate their potential for therapeutic applications. Beyond antibacterial applications, our findings establish LMPs as a transformative templating medium for the controlled fabrication of ultrathin 2D MOFs with enhanced functional properties.