Optimization of the biosynthesis of copper nanoparticles using Ananas comosus (MD2) leaves extract and their in vitro antifungal activity against Fusarium solani, Curvularia spp., and Colletotrichum gloeosporioides

Environmental issues have arisen due to the substantial quantity of agricultural waste, particularly from the leaves of Ananas comosus (MD2). This research suggests a sustainable method by utilizing leaves gathered from Chin Chin, Melaka for the green synthesis of CuNPs, providing a cost-efficient and adaptable technique. The leaves extract serves as a reducing, capping, and stabilizing agent for aqueous CuSO₄ in the production of CuNPs with antifungal characteristics. The synthesis process was optimized, revealing a pronounced SPR peak between 266 nm in UV Vis DRS analysis. FTIR analysis confirmed the presence of functional groups associated with flavonoids, alkaloids, and terpenoids, which played a role in stabilization. FESEM imaging displayed CuNPs with spherical shapes and sizes of 39.59 ± 10.4 nm with 75.03% copper elemental composition. HRTEM measurements indicated spherical atomic shapes with 5.84 ± 1.3 nm in sizes. XRD and SAED analyses validated the crystalline structure, with peaks corresponding to the (111), (200), and (220) planes. After a month, stability assessments indicated that copper oxidation impacted the stability and structure of the CuNPs. Antifungal evaluations were performed using varying doses (2, 4, and 6 mL) of colloidal CuNPs against 20 μL of 1 × 10⁶ conidia/mL of Fusarium solani, Curvularia spp., and Colletotrichum gloeosporioides through the food poison method. The results demonstrated a reduction in fungal growth, achieving complete inhibition of Colletotrichum gloeosporioides at a dosage of 6 mL. The synthesized CuNPs exhibited the highest efficacy against this particular species. Statistical analysis revealed significant outcomes (p < 0.01) and vigorous correlations among treatment factors. These results underscore the potential of CuNPs synthesized using the extract of Ananas comosus (MD2) leaves as a promising antifungal agent for agricultural applications.