Organically modified biogenic graphene oxide–mesoporous silica nanoparticles for eco-friendly and tailored release of Azadirachtin (neem) biopesticide

Herein, a modified biogenic graphene oxide–mesoporous silica hybrid nanoparticle (GO–MSNs) was developed as a reliable and efficient nano-pesticide delivery system (nano-PDS) for the slow release of neem (Azadirachtin, Aza), which is known as an environmentally friendly biopesticide. For this purpose, GO–MSN-based nanocarrier (GO–MSNs) was synthesized using rice husk-derived silica and graphene precursors, followed by surface modification to obtain propyl amine-functionalized GO–MSNs nanocarrier (nano-PDS). The nano-PDS nanocarrier was then characterized and investigated for its potential as a nanoporous host for efficient loading and slow-release pattern of Aza to control the silverleaf whitefly (Bemisia tabaci). The nanostructure and porosity of the synthesized nanocarrier were fully characterized by X-ray diffraction (XRD), electron microscopy (SEM and TEM), thermogravimetric analysis (TGA), and surface area and pore analysis using the Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) theories. The loading efficiency was found to depend on nanocarrier characteristics, such as surface area, pore size, functional group, and surface charge. Notably, the interaction between Aza and the amine functional groups found in the nano-PDS led to a more efficient slow-release profile compared to the bare GO–MSNs nanocarrier. The release rate of Aza was analyzed using a UV–visible spectrophotometer at 214 nm. The UV stability, thermal stability, and release behavior as paramount factors in developing a sustainable Aza delivery system were tuned by manipulating the nanocarrier surface. The organically modified biogenic GO–MSNs thus offers promising potential for slow-release and improved efficiency of Aza-based nanobiopesticide in the control of Bemisia tabaci.