Unveiling Antibacterial and Antibiofilm Mechanisms of Methyleugenol: Implications for Ecomaterial Functionalization

Bacterial resistance evolution necessitates the continuous adaptation of antimicrobial agents. In this study, we systematically investigated the antibacterial and biofilm-inhibition mechanisms of plant extracts, including methyleugenol and eugenol, and further explored their potential for immobilization in practical applications. Our findings revealed that eugenol exhibited robust antibacterial activity by disrupting bacterial redox balance and membrane permeability. Methyleugenol, on the other hand, efficiently mitigated biofilm formation by inhibiting the quorum sensing (QS) system and depolarizing the cell membrane. Through gene expression analysis and molecular docking studies, we confirmed that methyleugenol suppressed the transcriptional expression of QS regulatory genes by competitively binding to the RhlR receptor protein, thereby reducing the secretion of extracellular polymeric substances and inhibiting the biofilm formation. Furthermore, we observed an upregulation of multiple efflux pump MexAB-OprM as a response to bacterial reductive stress during compound exposure. To expand the practical utility of these findings, we successfully grafted methyleugenol onto glass surfaces using the atom transfer radical polymerization method, demonstrating enduring antibacterial and antibiofilm properties. Overall, our study offers a comprehensive understanding of the antibacterial and antibiofilm mechanisms of methyleugenol and eugenol, with promising applications for enhancing ecomaterial functionalization

High Performance Nanofiltration Membrane for Effective Removal of Perfluoroalkyl Substances at High Water Recovery

We demonstrate the fabrication of a loose, negatively charged nanofiltration (NF) membrane with tailored selectivity for the removal of perfluoroalkyl substances with reduced scaling potential. A selective polyamide layer was fabricated on top of a poly­(ether sulfone) support via interfacial polymerization of trimesoyl chloride and a mixture of piperazine and bipiperidine. Incorporating high molecular weight bipiperidine during the interfacial polymerization enables the formation of a loose, nanoporous selective layer structure. The fabricated NF membrane possessed a negative surface charge and had a pore diameter of ∼1.2 nm, much larger than a widely used commercial NF membrane (i.e., NF270 with pore diameter of ∼0.8 nm). We evaluated the performance of the fabricated NF membrane for the rejection of different salts (i.e., NaCl, CaCl₂, and Na₂SO₄) and perfluorooctanoic acid (PFOA). The fabricated NF membrane exhibited a high retention of PFOA (∼90%) while allowing high passage of scale-forming cations (i.e., calcium). We further performed gypsum scaling experiments to demonstrate lower scaling potential of the fabricated loose porous NF membrane compared to NF membranes having a dense selective layer under solution conditions simulating high water recovery. Our results demonstrate that properly designed NF membranes are a critical component of a high recovery NF system, which provide an efficient and sustainable solution for remediation of groundwater contaminated with perfluoroalkyl substances

Strain and Interference Synergistically Modulated Optical and Electrical Properties in ReS₂/Graphene Heterojunction Bubbles

Two-dimensional (2D) material bubbles, as a straightforward method to induce strain, represent a potentially powerful platform for the modulation of different properties of 2D materials and the exploration of their strain-related applications. Here, we prepare ReS2/graphene heterojunction bubbles (ReS2/gr heterobubbles) and investigate their strain and interference synergistically modulated optical and electrical properties. We perform Raman and photoluminescence (PL) spectra to verify the continuously varying strain and the microcavity induced optical interference in ReS2/gr heterobubbles. Kelvin probe force microscopy (KPFM) is carried out to explore the photogenerated carrier transfer behavior in both strained ReS2/gr heterobubbles and ReS2/gr interfaces, as well as the oscillation of surface potential caused by optical interference under illumination conditions. Moreover, the switching of in-plane crystal orientation and the modulation of optical anisotropy of ReS2/gr heterobubbles are observed by azimuth-dependent reflectance difference microscopy (ADRDM), which can be attributed to the action of both strain effect and interference. Our study proves that the optical and electrical properties can be effectively modulated by the synergistical effect of strain and interference in a 2D material bubble