Green-synthesized tellurium nanoparticles as a multifunctional leather finishing agent: antimicrobial and mechanical enhancement.

Leather is highly susceptible to microbial colonization due to its moisture retention and nutrient-rich structure, which promotes bacterial and fungal growth and compromises hygiene, durability, and user comfort in applications such as footwear and upholstery. In this work, tellurium nanoparticles (TeNPs) were green synthesized through redox reaction using plant extract and structurally characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) to confirm crystalline phase, particle size, and morphology. The TeNPs were then applied to leather substrates to generate antimicrobial leathers. The distribution and surface morphology of TeNPs on leather were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) to verify nanoparticle anchoring and elemental composition. Mechanical performance was assessed through tensile strength and elongation testing to evaluate the influence of TeNP incorporation on the integrity of the leather matrix. Antibacterial and antifungal activities of TeNP-treated leather were quantified against representative Gram-positive and Gram-negative bacteria and Aspergillus fungal. The antimicrobial efficacy of TeNPs is attributed to ROS generation, disruption of microbial cell membranes, inhibition of thiol-containing respiratory enzymes, and Te redox cycling-mediated oxidative stress, which together achieve broad-spectrum inactivation of bacterial and fungal pathogens. The TeNP-functionalized leather exhibited pronounced antibacterial and antifungal activities while enhancing mechanical performance, indicating its potential as a high-value, hygienic leather material for advanced footwear and other consumer applications.