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Bio-assembly of CdS <sub/>x</sub> Se <sub/>1?x</sub> quantum dots in ryegrass
摘要： CdSxSe1?x quantum dots (QDs) were self-assembled in Lolium perenne. Root apical meristem, root hair and leaf apex were the ‘hot spots’ of QD formation. Not only the yield of QDs but also their chemical composition varied in di?erent tissues: higher Cd–S/Cd–Se ratios were identi?ed in stems and leaves than in roots.
关键词： Biosynthesis,Green Chemistry,Ryegrass,Quantum Dots,CdSxSe1?x
更新于2025-09-12 10:27:22
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Enabling highly efficient photocatalytic hydrogen generation and organics degradation <i>via</i> a perovskite solar cell-assisted semiconducting nanocomposite photoanode
摘要： The halogenase gene spmH was putatively involved in the biosynthesis of spiroindimicins/indimicins (SPMs/IDMs), a group of chlorinated tryptophan dimers (TDs) from deep-sea-derived Streptomyces sp. SCSIO 03032. Inactivation of spmH led to six deschloro-analogues of TDs, including four new compounds SPMs G (1) and H (2), and IDMs F (3) and G (4). The structures and absolute configurations of 1–4 were unambiguously determined by the combination of extensive spectroscopic analysis, single-crystal X-ray diffraction and quantum chemical ECD calculations. Compounds 1 and 2 exhibited moderate cytotoxic activities against four cancer cell lines. Additionally, SpmH was biochemically characterized in vitro as an L-tryptophan 5-halogenase.
关键词： L-tryptophan 5-halogenase,biosynthesis,tryptophan dimers,cytotoxic activities,halogenase
更新于2025-09-11 14:15:04
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Enhanced biosynthesis of CdS nanoparticles through Arabidopsis thaliana phytochelatin synthase-modified Escherichia coli with fluorescence effect in detection of pyrogallol and gallic acid
摘要： In this work, CdS nanoparticles (CdS NPs) biosynthesized through Arabidopsis thaliana phytochelatin synthase-modified Escherichia coli (CdS/AtPCS1-E. coli) with fluorescence (FL) performance for detection of pyrogallol and gallic acid was investigated. Through expression of the AtPCS1 gene inside E. coli cells by pET28b vector, biosynthesis of CdS NPs was greatly enhanced due to generation of phytochelatins (PCs, (γ-Glu-Cys)n-Gly, n ≥ 2) for efficient capture of Cd2+. The expression of AtPCS1 and concentration of glutathione (GSH) and PCs were detected by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and high performance liquid chromatography (HPLC), respectively. The morphology and component were checked through scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS). FL effect with different experimental conditions were examined. In addition, it is also applied to determination of pyrogallol and gallic acid. These results revealed that multifunctional PCs could effectively facilitate biosynthesis of CdS NPs with higher yield, better distribution and lower cost while stronger FL intensity could be obtained for quantitative analysis.
关键词： CdS nanoparticles,Escherichia coli,Phytochelatin,Fluorescence performance,Biosynthesis
更新于2025-09-09 09:28:46
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EXTRACELLULAR AND INTRACELLULAR SYNTHESIS OF SILVER NANOPARTICLES
摘要： The cellular synthesis of nanoparticle is a green process and alternative for a conventional process for the preparation of silver nanoparticles. In our research, focus has been given to the development of an efficient and eco-friendly viable process for the synthesis of silver nanoparticles using cancer and non-cancerous cells, a cell culture that was isolated. The results of this investigation are observed that silver nanoparticles could be induced to synthesis intra- and extra-cellularly using mammalian cells such as cancerous and non-cancerous cells. The silver nanoparticles are synthesized by the cancer and non-cancerous cells such as HeLa (Homo sapiens, human), SiHa, and human embryonic kidney-293 cell lines. The silver nanoparticles were characterized by ultraviolet (UV)-visible spectroscopy, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). The silver nanoparticles exhibited maximum absorbance at 415 nm in UV-visible spectroscopy. The XRD confirms the characteristic of the crystal lattice of silver nanoparticles by observing three peaks: Peak at 38 is due to reflection from (111), peak at 44 is due to reflection from (200), and peak at 65 is due to reflection from (220). TEM images showed the formation of stable silver nanoparticles in the cell lines. The method of extraction of intracellular/extracellular synthesis of silver nanoparticles was inexpensive, simple, and effective in large scale with no need to use of complex process equipment. The cancer cell considered as a biological factory at nanoscale dimension which continued to grow after synthesis of silver nanoparticles. The silver reduction by these cancer cells has occurred through energy-dependent processes that lead to the high output of this reaction. Hence, this new approach of using a mammalian cell for the successful synthesis of nanosized silvers could be easily scaled up, which establishes its commercial viability and also useful in the drug delivery and drug targeting.
关键词： Cancer cells,Biosynthesis and characteristics of silver nanoparticles,Silver nanoparticles
更新于2025-09-09 09:28:46
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Bio-hydrometallurgy dynamics of copper sulfide-minerals probed by micro-FTIR mapping and Raman microspectroscopy
摘要： We report the μm-FTIR mapping and Raman microspectroscopic detection of bornite [Cu5FeS4]-, chalcocite [Cu2S]-, and covelitte [CuS]- bacterial interactions by a consortium of microorganisms consisted of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Leptospirillum ferriphilum, Leptospirillum ferroodiazotrophum and Sulfobacillus thermosul?dooxidans. The absorption signals of amide I, K+-jarosite [KFe3(SO4)2(OH)6] and of the produced extracellular polymeric substances (EPS) from the mixed culture as a function of position on the surfaces of the bioleached bornite, chalcocite and covellite demonstrated their heterogeneity within the surface of the minerals. This reveals the high level of bio?lm, EPS, and jarosite biosynthesis on the surface of the minerals and might explain why they associate. To our knowledge this is the ?rst combined application of μm-FTIR mapping and Raman microspectroscopy for the bioleaching behaviour of bornite, chalcocite and covellite and the comparison with other bioleached systems such as chalcopyrite [CuFeS2] provides valuable information on the whole bio-hydrometallurgy Cu/Fe/S system. Both techniques provide spectrally rich, label-free, nondestructive visualizations of the bio-hydrometallurgy dynamics of copper sul?de minerals for processing and storage of large spectral data sets which are valuable for evaluation of copper containing minerals.
关键词： Micro-FTIR mapping,Copper sul?de minerals,Bio?lm formation,Jarosite biosynthesis,Raman
更新于2025-09-09 09:28:46
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Biosynthesis of Silver Nanoparticles Using <i>Selaginella bryopteris</i> Plant Extracts and Studies of Their Antimicrobial and Photocatalytic Activities
摘要： The present study focuses on the green synthesis of silver nanoparticles (AgNPs) using aqueous extract of S. bryopteris which is a lithophyte with remarkable resurrection capabilities. These biosynthesized NPs were characterized with the help of UV-vis spectrophotometer, X-ray diffraction (XRD), FT-IR and Transmission electron microscopy (TEM). Formation of AgNPs was confirmed by UV-Visible spectrophotometer analysis which showed surface plasmon resonance (SPR) at around 420 nm. The TEM images showed the nanoparticles to be polydispersed, nearly spherical in shape and have sizes in range 4–30 nm. The synthesized AgNPs possessed high antibacterial activity as well as photocatalytic dye degradation properties under solar light irradiation in the absence of chemical reducing reagents. Stability of bio-reduced silver nanoparticles was analyzed using UV-vis absorption spectra, and their antimicrobial activity was screened against various gram-positive bacteria.
关键词： Characterization,Photodegradation,Antimicrobial Activity,Biosynthesis,S. bryopteris Extract,Silver Nanoparticles
更新于2025-09-04 15:30:14