Ultrastructural changes in the fat body of desert locust, Schistocerca gregaria (Orthoptera: Acrididae) treated with zinc chromium oxide nanostructures via chemical co-precipitation approach

Abstract

The present work aims to investigate the ultrastructural changes in the fat body of fifth instar nymphs Schistocerca gregaria (Orthoptera: Acrididae) treated with zinc chromium oxide (ZnCrO). The nanoparticles (NPs) were prepared by co-precipitation route and characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The ZnCrO NPs exhibited polycrystalline hexagonal structure, composed of spherical–hexagonal shapes with an average size ~ 25 nm. Besides, the UV–Vis spectrophotometer (Jasco-V-570) was utilized for optical measurements. The energy gap $$\left( {{\text{E}}_{{\text{g}}} } \right)$$ E g was estimated from the transmittance (T%) and reflectance (R%) spectra through the range of 3.307–3.840 eV. In biological sections, S. gregaria 5th instar nymphs, TEM images demonstrated that the fat body was strongly impacted with the concentration 2 mg NPs result in great agglomeration of chromatin in the nucleus as well as haemoglobin cells (HGCs) pierced with malformed trachea (Tr) at 5th and 7th days post treatment. The obtained results indicated a positive action of the prepared nanomaterial on Schistocerca gregaria fat body organelles. Graphical Abstract

The high impact of zinc chromium oxide nanocombs on development of larvicidal and antimicrobial performance

“…The optical reflectance displayed peaks and valleys ascribed to electron-photon interaction or electron scattering, Fig. 4b [34,35]. The optical absorption coefficient (α) was calculated from T% and R% using the following relation:…”

“…The thin film exhibits an optical absorption peak at ~3.20 eV in which the electron absorbs incident photon energy and jumps to the conduction band leading to increased free charge carriers [34]. For further optical analysis, the optical band gap (E g ) was determined from Tauc's equation expressed as [35]:…”

“…5b. The wide energy gap emphasizes the quantum size effect of the nanocomposite which is attributed to the large surface area and reactive surface sites [35,36].…”