Eco-friendly protection of pine wood using copper nanoparticles biosynthesized from Cleistocalyx operculatus leaf extracts

This research investigates the eco-friendly biosynthesis of copper nanoparticles (CuNPs) from Cleistocalyx operculatus (water banyan) leaf extracts for the sustainable preservation of pine wood Pinus kesiya (khasi pine). The study specifically targets protection against common wood-decaying fungi, including Aspergillus flavus ATCC 9643, Fusarium oxysporum ATCC 48112, and Penicillium citrinum ATCC 9849, as well as termites. CuNPs were synthesized under optimized conditions: 80 °C for 30 minutes using a rotary evaporator, at pH 11, with 20 mM copper sulfate, and a 1.5:1 plant extract to precursor ratio. Comprehensive characterization using UV-Vis spectroscopy confirmed a prominent absorption peak at 595 nm. Scanning Electron Microscopy and Transmission Electron Microscopy further validated their spherical morphology, high crystallinity, and an average size of 2 ± 1 nm. Wood durability was evaluated through laboratory tests of fungal and termite resistance To assess the effects of different CuNPs treatments on fungal resistance and termite resistance, a one-way ANOVA was employed. Significant differences were found among the treatment groups (P