Synergistic Antifungal Activity of Dialdehyde Chitosan Loaded with Copper Metal‐Organic Framework (Cu‐MOF)

Abstract Fungal resistance and the environmental degradation posed by conventional fungicides necessitate the need to develop new antifungal agents that can inhibit fungal growth. This study sought to prepare biofungicides by leveraging on the antifungal activity of copper‐metal organic framework (Cu‐MOF) and dialdehyde chitosan (Cs) isolated from black soldier flies (BSF). Cs were oxidized using potassium periodate to obtain dialdehyde Cs (OCs) and thereafter, Cu‐MOF was loaded resulting in Cu‐MOF‐OCs. Fourier Transform Infrared spectrophotometer (FT‐IR) and powder X‐ray diffraction (XRD) confirmed the presence of carbonyl functional groups in OCs and sharp intense peaks associated with Cu that interacted. The changes in surface morphology and the presence of Cu in the MOFs as obtained with Scanning Electron Microscope‐ Energy Dispersive X‐ray (SEM‐EDX), indicated the successful loading of Cu‐MOF on the oxidized Cs. Thermogravimetric analysis (TGA) showed a loss of approximately 31.51 % of the loaded OCs and 40.72 % framework around ∼200 to ∼300 °C and ∼410 to ∼475 °C respectively. The antifungal activity of OCs, Cu‐MOF, and Cu‐MOF‐OCs against Aspergillus brasiliensis and Candida albicans was performed using the plate count method and the results suggested that MOF modulated the antifungal activity exerted by the OCs.