In the present study, we focused on a quick and green method to fabricate Ag, Au and Ag/Au alloy nanoparticles (NPs) using the bark extract of Guazuma ulmifolia L. Green synthesized metal NPs were characterized using different techniques, including UV-Vis spectroscopy, FT-IR, XRD, AFM and HR-TEM analyses. The production of Ag, Au and Ag/Au alloy NPs was observed monitoring color change from colorless to brown, followed by pink and dark brown, as confirmed by UV-Vis spectroscopy characteristic peaks at 436, 522 and 510nm, respectively. TEM shed light on the spherical shapes of NPs with size ranges of 10-15, 20-25 and 10-20nm. Biosynthesized NPs showed good catalytic activity reducing two organic dyes, 4-nitrophenol (4-NP) and Congo red (CR). UV-vis spectroscopy, fluorescence, circular dichroism spectroscopy and viscosity analyses were used to investigate the NP binding with calf thymus DNA. The binding constant of NPs with DNA calculated in UV-Vis absorption studies were 1.18×10, 1.83×10 and 2.91×10M, respectively, indicating that NPs were able to bind DNA with variable binding affinity: Ag/Au alloy NPs>Ag NPs>Au NPs. Ag/Au alloy NPs also showed binding activity to bovine serum albumin (BSA) over the other NPs. Ag and Ag/Au alloy NPs exhibited good antimicrobial activity on 14 species of microbial pathogens. In addition, the cytotoxic effects of Ag/Au alloy NPs were studied on human cervical cancer cells (HeLa) using MTT assay. Overall, our work showed the promising potential of bark-synthesized Ag and Ag/Au alloy NPs as cheap sources to develop novel and safer photocatalytic, antimicrobial and anticancer agents.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jphotobiol.2017.01.008 | DOI Listing |
J Chem Phys
December 2024
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Rotational excitations of reactants are often considered to have little impact on chemical reactivity compared to the excitations of vibrational modes and translational motion. Here, we reveal a significant influence of the rotational excitation of HCl on its dissociation on an Ag/Au(111) alloy surface. This finding is based on six-dimensional time-dependent wave packet calculations performed on an accurately fitted machine learning potential energy surface.
View Article and Find Full Text PDFAnal Chem
November 2024
Guangxi Key Laboratory of Green Processing of Sugar Resources, Department of Medicine, College of Biological and Chemical Engineering, Guangxi University of Science and Technology, Liuzhou 545006, Guangxi, P. R. China.
In this study, we developed ratiometric surface-enhanced Raman scattering (SERS) biosensors using Ag-Au alloy nanoflowers as SERS substrates, molecules having amide bonds and alkyne groups (Tag A) as Raman reporters, and sodium thiocyanate as an internal standard molecule (Tag B) for the sensitive detection of human carboxylesterase-1 (hCE1) in HepG-2 cells. The correlation between HepG-2 cell damage and hCE1 activity levels was investigated. Both Tag A's alkyne group and Tag B's cyanide group produced characteristic SERS signals in the Raman-silent region ( and , respectively).
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
Department of Materials Science and Engineering, University of California - Davis, Davis, California 95616, United States.
Metal alloy nanostructures represent a promising platform for next-generation nanophotonic devices, surpassing the limitations of pure metals by offering additional "buttons" for tailoring their optical properties by compositional variations. While alloyed nanoparticles hold great potential, their scalability and underexplored optical behavior still limit their application. Here, we establish a systematic approach to quantifying the unique optical behavior of the AgAuPd ternary system while providing a direct comparison with its pure constituent metals.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2024
Department of Mechanical and Nuclear Engineering, Khalifa University of Science and Technology, Main Campus, P.O. Box 127788 Abu Dhabi, UAE.
N activation is a vital step in the process toward NH production. NH synthesis has been considered a crucial process for the production of value-added chemicals and/or hydrogen carriers over recent years. In this work, density functional theory (ab initio) calculations are implemented for a thorough screening of bimetallic alloy surfaces using Fe, Ru, and Mo as the matrix (host) metals and Ag, Au, Co, Cu, Fe, Mo, Ni, Pd, Pt, Rh, and Rh as heterometals toward exploring the N catalytic activation (electronic and chemical characteristics); the monometallic surfaces are used for critical comparison in terms of their N activation behavior.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!