Engineered 3D MXene- and GO-based Ag nanocomposites with enhanced stability and antibacterial performance

Official URL: https://dx.doi.org/10.1016/j.flatc.2026.101052

Silver-containing systems are among the most promising antibacterial strategies. However, their practical efficacy is frequently compromised by the instability, aggregation, and uncontrolled oxidative dissolution of silver nanoparticles (AgNPs). This study explores the development of hybrid 3D systems utilizing graphene oxide (GO) and MXene nanosheets as functional scaffolds for stabilized AgNPs. 2D nanosheets were crosslinked with an organic silane, N , N ′-bis(3-(triethoxysilyl)propyl)urea (Bis-urea), which performs both as a reducing agent for Ag+, confining their size and growth location, and inhibiting the aggregation of the 2D nanosheets. The resulting 3D nanocomposites exhibit a hierarchical architecture in which agglomeration of AgNPs is restricted by 2D nanosheets, while the intercalated silane linkers and AgNPs prevent restacking of GO and MXene nanosheets. The synthesized nanohybrids and nanocomposites were characterized using XRD, FTIR, Raman, TGA, SEM, TEM, and XPS to confirm every step of modification. Moreover, the zeta potential and size distribution were measured using DLS to provide insight into the surface charge and formation of nanocomposites. The zeta potentials were determined to be −23.13 mV and − 19.38 mV for the GO-based and MXene-based nanocomposites, respectively, both of which are more negative than that of Bis-urea/Ag (−18.46 mV). Antibacterial assays against E. coli and S. aureus revealed synergistic enhancement. Notably, MIC values of the MXene-based nanocomposites were reduced by 64-fold against E. coli and 125-fold against S. aureus , while the GO-based nanocomposites exhibited 16-fold and 8-fold reductions in MIC values against E. coli and S. aureus , respectively. At 1/2 MIC, over 90% reduction in colony forming unit (CFU) was observed, indicating a pronounced bactericidal effect of all samples. This performance stems from a combined mechanism: the “nano-knife” effect of the 2D edges inducing physical membrane disruption, complemented by localized oxidative stress and sustained Ag+ release from the embedded nanoparticles.