Green synthesis of silver nanoparticles using Solanum indicum L. and their antibacterial,splenocyte cytotoxic potentials

Research on Chemical Intermediates - Green synthesis of silver nanoparticles was carried out using Solanum indicum L. plant extract as a reducing agent. The morphology of the AgNPs was determined...     

Aerva lanata flower extract mediated green synthesis of silver nanoparticles: Their characterization,in vitro antioxidants and antimicrobial investigations

The production of nanoparticles (NPs) using biological methods may lead to the enhancement of clean, non-hazardous, and environmentally acceptable procedures. With this context, in the present study silver nanoparticles (AgNPs) were synthesized using the flower extract of Aerva lanata (A. lanata). The following techniques, including UV–visible spectroscopy, XRD, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR), are used to study the crystalline nature, size, shape, and elemental composition of the biosynthesized AgNPs, and antimicrobial applications of the NPs also studied. In UV–visible spectroscopy results a strong absorbance peak at 425 nm confirmed the AgNPs. The SEM results confirmed the spherical shape of the NPs and their average size of 45.05 nm. X-ray diffractometry XRD spectra confirmed the crystalline nature of the AgNPs. Against the DPPH (2,2-diphenyl-1-picrylhydrazyl), nitric oxide and superoxide radicals, Alf-AgNPs and ascorbic acid had significant scavenging effects at higher concentration of 250 μg/mL, exhibited 65.76 ± 0.41% and 86.42 ± 0.69%, 78.39 ± 0.49% and 72.72 ± 0.14% and 70.79 ± 0.87% and 72.79 ± 0.33% inhibition, respectively. As produced AgNPs had strong antibacterial and moderate antifungal activities against pathogenic test bacterial strains viz. Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Klebsiella pneumonia (K. pneumonia) with the maximum zone of inhibition 15 ± 1.07 mm, 12 ± 0.96 mm, 14 ± 1.05 mm, and 15 ± 2.54 mm, respectively at maximum (75 μg/mL) concentration of AgNPs, and the zone of inhibition of fungal strains Aspergillus fumigatus (A. fumigatus) (9 ± 0.67 mm) and Candida albicans (C. albicans) (7 ± 0.75 mm) at 75 μg/mL. It was eventually concluded that the biosynthesized Alf-AgNPs showed promising antioxidant and antimicrobial agents with very low concentrations.     

磁性纳米颗粒固定化细菌纤维素酶的活性和稳定性

在氨水溶液中进行Fe+2和Fe+3离子共沉淀并水热处理后制得磁性纳米颗粒Fe3O4,通过戊二醛活化将纤维素酶固定于其上。采用基于响应面法的Box-Behnken法(BBD)优化了制备条件,如磁性纳米颗粒浓度、戊二醛浓度、酶浓度和交联时间。 BBD分析结果表明,用实验数据可合理调节二次模型。利用生成的基于统计数据的等高线评价了响应面的变化,以理解纳米颗粒和酶活性之间的关系。运用扫描电镜、X射线衍射和红外光谱表征了纳米颗粒上酶的尺寸、结构、形貌和结合情况。采用诸如pH值、温度、重复使用性和存储能力分析了固定化纤维素酶的活性和稳定性。发现固定后的纤维素酶表现出更好的稳定性和活性。