Phycologically synthesized ZnO nanoparticles: Enhancing growth, nutrition, biochemical efficiency, and silk quality in the Bombyx mori L.

Sustainable enhancement of silkworm growth and silk productivity remains a major challenge in modern sericulture due to the limited efficacy of conventional nutritional supplements. To overcome this constraint, the present study investigates brown marine algae–derived zinc oxide nanoparticles (ZnO NPs) as an eco-friendly nano-supplement for Bombyx mori . The synthesized ZnO NPs were comprehensively characterized to establish their physicochemical properties. Structural and morphological analyses confirmed the synthesis of high-purity ZnO NPs with a hexagonal wurtzite structure. The NPs were mostly near-spherical, showed minimal agglomeration, and had an average size of about 78 nm. UV–visible analysis showed a distinct absorption peak at 270 nm, confirming their nanoscale optical properties. Functional evaluation revealed that ZnO NPs supplementation improved survivorship, growth, and nutritional efficiency in a dose-dependent manner, with 150 ppm identified as the most effective concentration. At this level, immune performance was enhanced, as shown by an approximately 10.5% increase in total haemocyte count and a rise in all haemocyte types. Biochemical analysis revealed higher levels of proteins, glycogen, sugars, amino acids, and nucleic acids in major tissues, indicating improved metabolism and biosynthesis. Digestive and transaminase enzyme activities were also elevated, supporting better nutrient utilization. These physiological benefits led to improved cocoon and silk traits, including higher cocoon and shell weight, pupal weight, filament length, denier, and mechanical strength. Molecular docking showed protein-specific interactions of ZnO, with the notable binding to serine protease, providing insight into its biological effectiveness.