In the current scenario, many synthetic chemicals have used long-term to control pests and mosquitoes, leading to the resistance of strains and toxicity effect on human beings. To overcome the adverse problem in recent advances, the scientific community is looking into nanofabricated pesticides and mosquitoes. This study aims to synthesize the recyclable chitosan-coated cadmium nanoparticles (Ch-CdNps) using Plumeria alba flower extract, which was further applied for insecticidal and mosquitocidal activities. The synthesized Ch-CdNps were confirmed by UV spectroscopy and FTIR analysis. The XRD, TEM, and DLS results confirmed the crystallinity with a spherical shape at 80-100 nm. The insecticidal activity proves that Ch-CdNps inhibited Helicoverpa armigera and Spodoptera litura at 100 ppm. In mosquitocidal, LC50 values of larvicidal of 1st instar were 4.116, 4.33, and 4.564 µg/mL, and the remaining three stages of instars, pupicidal, adulticidal, longevity, fecundity, and ovicidal assays inhibit the Anopheles stephensi followed by Aedes aegypti and Culex quinquefasciatus. Further, the first-order kinetics of photocatalytic degradation of methylene blue and methyl orange was confirmed. Based on the obtained results, Ch-CdNps can inhibit the pest, mosquitoes, and photocatalytic degradation.
Conventionally, microalgal lipid extraction uses volatile organic compounds as an extraction solvent. However, these solvents are harmful to human and environmental health. Therefore, this study evaluated the feasibility of alternative green solvents, namely, ethanol, dimethyl carbonate (DMC), cyclopentyl methyl ether (CPME), and 2-methyltetrahydrofuran (2-MeTHF) in lipid extraction from Chlorella sp. via ultrasound-assisted extraction (UAE). This study indicated that extraction parameters, such as ethanol-to-2-MeTHF ratio, solvent-to-biomass ratio, temperature, and time, significantly affected the crude lipid yield (P
This study used Morinda citrifolia leaf (MCL) extract to synthesise Zinc oxide nanoparticles (ZnO NPs) and ZnO decorated silver nanocomposites (ZnO/Ag NCs). The synthesized nanomaterials structural morphology and crystallinity were characterized using a Field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) analysis. The antimicrobial activity of ZnO NPs and ZnO/Ag NCs was evaluated using human nosocomial bacterial pathogens. The highest antimicrobial activity was recorded for ZnO/Ag NCs at the minimum inhibitory concentration (MIC) at 80 and 100 μg/mL for Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis, Staphylococcus aureus than ZnO NPs at the MIC of 120 and 140 μg/mL for Bacillus subtilis and Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus. Furthermore, ROS detection, viability assay and bacterial membrane integrity analysis of ZnO/Ag NCs treated P. aeruginosa and S. aureus revealed the fundamental bactericidal mechanism involving cell wall, cell membrane interaction and release of cytoplasmic contents. In addition, ZnO/Ag NCs and ZnO NPs showed higher toxicity towards A549 lung cancer cells than the non-cancerous RAW264 macrophage cells, with IC50 of 242 and 398 µg/mL respectively, compared to IC50 of 402 and 494 µg/mL for the macrophage cells. These results suggest that the ZnO/Ag NCs can be effectively used to develop antimicrobial and anticancer materials.
Alternanthera sessilis (AS) leaf extract was used to synthesize zinc oxide nanoparticles (ZnO NPs). Bioanalytical characterization techniques such as X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) confirmed the formation of crystalline ZnO NPs with average sizes of 40 nm. The AS-ZnO NPs antimicrobial activity was analyzed under dark (D) and white light (WL) conditions. The improved antimicrobial activity was observed against Escherichia coli, Staphylococcus aureus and Bacillus subtilis at the minimal inhibitory concentration (MIC) of 125 and 62.5 µg/mL under WL than the D at 125 and 250 µg/mL for E. coli, B. subtilis, and Pseudomonas aeruginosa, respectively. In contrast, the growth of P. aeruginosa and S. aureus was not completely inhibited until 1 mg/mL AS-ZnO NPs under WL and D. Similarly, AS-ZnO NPs displayed a weaker inhibitory effect against carbapenem-sensitive P. aeruginosa (CSPA) and carbapenem-resistant P. aeruginosa (CRPA) strains of PAC023, PAC041 and PAC032, PAC045 under D. Interestingly, the distinct inhibitory effect was recorded against CSPA PAC041 and CRPA PAC032 in which the bacteria growth was inhibited 99.9% at 250, 500 µg/mL under WL. The cytotoxicity results suggested AS-ZnO NPs demonstrated higher toxicity to MCF-7 breast cancer cells than the RAW264.7 macrophage cells. Further, AS-ZnO NPs exhibited higher catalytic potential against tetracycline hydrochloride (TC-H) degradation at 65.6% and 60.8% under WL than the dark at 59.35% and 48.6% within 120 min. Therefore, AS-ZnO NPs can be used to design a photo-improved antimicrobial formulation and environmental catalyst for removing TC-H from wastewater.