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Biosynthesis of nickel ferrite (NiFe2O4) nanoparticles (NPs) using an aqueous extract of Murraya koenigii (M. koenigii) leaves is a novel, environmentally benign and cost effective method. NiFe2O4 NPs were characterized by different spectroscopic and microscopic techniques, including Ultraviolet–Visible (UV–Vis) spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), High-Resolution Scanning Electron Microscopy (HRSEM), Energy-dispersive X-ray spectrometry (EDX) and Vibrating-Sample Magnetometer (VSM). The observed results revealed that prepared NiFe2O4 NPs are highly pure, crystalline, partially spherical with an average size of 2–6 nm and attribute magnetic properties. The magnetization of the obtained biosynthesized nanoparticles is noticed ∼5.2 emu/g at 10 K Oe. The NiFe2O4 NPs exhibited a heterogeneous photo Fenton's catalytic feature in the presence of oxalic acid at ambient conditions. The effects of pH, dosage of NiFe2O4 catalyst and doses of oxalic acid on the degradation efficiency of 10 mg/L MB dye were assessed. The optimal degradation efficiency of ⁓ 98.5% was achieved within 70 min, and the observed results elucidated that the photocatalytic reactions follow first-order chemical kinetics. Thermodynamic parameters such as activation energy (Ea), enthalpy of activation (ΔH‡), entropy of activation (ΔS‡), and free energy of activation (ΔG‡) were evaluated, applying Arrhenius and activated complex theory ascertained the endothermic, less random and nonspontaneous features of photocatalytic process. NiFe2O4 NPs were also tested against different bacteria and found to have antibacterial properties. Hence, magnetic NiFe2O4 NPs can be exploited for its multifunctional applications, and specifically for the remediation of dye-contaminated wastewater.

The issue of organic contaminants in water resulting from industrial, agricultural, and home activities makes it necessary to effectively address the problems of water scarcity. Using modern technologies that can effectively remove pollutants from wastewater is the way to address this key problem. The use of nanoparticles (NPs) has been advocated due to their unique physical and chemical characteristics and advantageous applications. NPs’ surface stability and synthesis routes are core concerns for environmental remediation and biological applications. In this work, we demonstrated the biogenic synthesis of silver NPs (Ag-CS NPs) by using Caralluma subulata (CS) aqueous extract as a reducing and capping/template agent. The synthesized Ag-CS NPs were characterized by UV-visible absorbance spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, powdered X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Zeta potential. The performance of Ag-CS NPs was evaluated on methylene blue (MB) dye degradation and antibacterial activity tests against bacterial and fungal isolates. The results showed that Ag-CS NPs (0.05%, 20.0 μL) reduced MB by 95.52% within 28 min in the presence of NaBH4 (10.0 mM, 0.980 μL). The degradation of MB followed pseudo zero-order chemical kinetics (R2 = 0.9380), with the reaction rate constant 0.0508 mol L−1 min−1. In addition, Ag-CS NPs were applied as antibacterial agents against 19 bacterial isolates. Ag-CS NPs showed inhibition in both Gram-positive and Gram-negative bacterial, as well as fungal isolates. As a greener ecofriendly approach, multifunctional Ag-CS NPs make a promising candidate for the remediation of contaminated water, as well as for important bioapplications.

The medicinal administration of Aloe vera gel has become promising in pharmaceutical and cosmetic applications particularly with the development of the nanotechnology concept. Nowadays, effective H. pylori treatment is a global problem; therefore, the development of natural products with nanopolymers such as chitosan nanoparticles (CSNPs) could represent a novel strategy for the treatment of gastric infection of H. pylori. HPLC analysis of A. vera gel indicated the presence of chlorogenic acid as the main constituent (1637.09 µg/mL) with other compounds pyrocatechol (1637.09 µg/mL), catechin (1552.92 µg/mL), naringenin (528.78 µg/mL), rutin (194.39 µg/mL), quercetin (295.25 µg/mL), and cinnamic acid (37.50 µg/mL). CSNPs and A. vera gel incorporated with CSNPs were examined via TEM, indicating mean sizes of 83.46 nm and 36.54 nm, respectively. FTIR spectra showed various and different functional groups in CSNPs, A. vera gel, and A. vera gel incorporated with CSNPs. Two strains of H. pylori were inhibited using A. vera gel with inhibition zones of 16 and 16.5 mm, while A. vera gel incorporated with CSNPs exhibited the highest inhibition zones of 28 and 30 nm with resistant and sensitive strains, respectively. The minimal inhibitory concentration (MIC) was 15.62 and 3.9 µg/mL, while the minimal bactericidal concentration (MBC) was 15.60 and 7.8 µg/mL with MBC/MIC 1 and 2 indexes using A. vera gel and A. vera gel incorporated with CSNPs, respectively, against the resistance strain. DPPH Scavenging (%) of the antioxidant activity exhibited an IC50 of 138.82 μg/mL using A.vera gel extract, and 81.7 μg/mL when A.vera gel was incorporated with CSNPs. A.vera gel incorporated with CSNPs enhanced the hemolysis inhibition (%) compared to using A.vera gel alone. Molecular docking studies through the interaction of chlorogenic acid and pyrocatechol as the main components of A. vera gel and CSNPs with the crystal structure of the H. pylori (4HI0) protein supported the results of anti-H. pylori activity.