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Graphene biofilm

Jian-Zhou He, Deng-Jun Wang, Huan Fang, Qing-Long Fu, Dong-Mei Zhou
Increasing production and use of graphene oxide nanoparticles (GONPs) boost their wide dissemination in the subsurface environments where biofilms occur ubiquitously, representative of the physical and chemical heterogeneities. This study aimed at investigating the influence of Gram-positive Bacillus subtilis (BS) and Gram-negative Pseudomonas putida (PP) biofilms on the transport of GONPs under different ionic strengths (0.1, 0.5, and 1.0 mM CaCl2) at neutral pH 7.2 in water-saturated porous media. Particularly, the X-ray micro-computed tomography was used to quantitatively characterize the pore structures of sand columns in the presence and absence of biofilms...
November 14, 2016: Chemosphere
Valentina Palmieri, Massimiliano Papi, Claudio Conti, Gabriele Ciasca, Giuseppe Maulucci, Marco De Spirito
The clinical challenge that research on antibacterial coatings faces nowadays is the need of reduction of resistant bacterial infections, major source of implant rejection and repeated surgery. In order to avoid microorganisms attachment and biofilm formation, coating materials on medical devices have been developed with shortcomings represented by short-term durability and induction of new mechanisms of bacterial resistance. Graphene-based films and hydrogel could represent the next generation protective coatings due to their excellent mechanical, chemical and thermal properties, high nanoparticle adsorption and antibacterial action...
October 6, 2016: Expert Review of Medical Devices
Haiwei Ji, Kai Dong, Zhengqin Yan, Chao Ding, Zhaowei Chen, Jinsong Ren, Xiaogang Qu
A novel platform for targeted on-demand prodrug ascorbic acid (AA) delivery is fabricated using a bacterial hyaluronidase sensitive graphene-mesoporous silica nanosheet@hyaluronic acid-magnetic nanoparticles as the nanocarrier to treat bacterial infections. The released AA can be converted to detrimental •OH in situ on the surface of bacteria. With the chemo-photothermal synergistic effect, the designed antibacterial system can effectively inactivate bacteria and disperse stubborn biofilm.
December 2016: Small
Maxine Swee-Li Yee, Poi-Sim Khiew, Wee Siong Chiu, Yuen Fen Tan, Yih-Yih Kok, Chee-Onn Leong
Fouling of marine surfaces has been a perpetual problem ever since the days of the early sailors. The tenacious attachment of seaweed and invertebrates to man-made surfaces, notably on ship hulls, has incurred undesirable economic losses. Graphene receives great attention in the materials world for its unique combination of physical and chemical properties. Herein, we present a novel 2-step synthesis method of graphene-silver nanocomposites which bypasses the formation of graphene oxide (GO), and produces silver nanoparticles supported on graphene sheets through a mild hydrothermal reduction process...
September 9, 2016: Colloids and Surfaces. B, Biointerfaces
Jingchun Li, Xuyang Liu, Jiaqi Lu, Yudan Wang, Guanglu Li, Fangbo Zhao
To improve the anti-biofouling properties of PVDF membranes, GO-Ag composites were synthesized and used as membrane antibacterial agent by a simple and environmentally friendly method. As identified by XRD, TEM and FTIR analysis, AgNPs were uniformly assembled on the synthesized GO-Ag sheets. The membranes were prepared by phase inversion method with different additional amounts (0.00-0.15wt%) of GO-Ag composites. The GO-Ag composites modified membranes show improved hydrophilicity, mechanical property and permeability than unmodified PVDF membrane...
December 15, 2016: Journal of Colloid and Interface Science
Achyut Konwar, Sanjeeb Kalita, Jibon Kotoky, Devasish Chowdhury
We report a robust biofilm with antimicrobial properties fabricated from chitosan-iron oxide coated graphene oxide nanocomposite hydrogel. For the first time, the coprecipitation method was used for the successful synthesis of iron oxide coated graphene oxide (GIO) nanomaterial. After this, films were fabricated by the gel-casting technique aided by the self-healing ability of the chitosan hydrogel network system. Both the nanomaterial and the nanocomposite films were characterized by techniques such as scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, and vibrating sample magnetometry...
August 17, 2016: ACS Applied Materials & Interfaces
Zhaojun Jia, Yuying Shi, Pan Xiong, Wenhao Zhou, Yan Cheng, Yufeng Zheng, Tingfei Xi, Shicheng Wei
Bringing multifunctional graphene out of solution through facile self-assembly to form 2D surface nanostructures, with control over the lateral size and surface properties, would be an intriguing accomplishment, especially in biomedical fields where biointerfaces with functional diversity are in high demand. Guided by this goal, in this work, we built such graphene-based self-assemblies on orthopedic titanium, attempting to selectively regulate bacterial activities and osteoblastic functions, which are both crucial in bone regeneration...
July 13, 2016: ACS Applied Materials & Interfaces
Tian-Shun Song, Yuejuan Jin, Jingjing Bao, Dongzhou Kang, Jingjing Xie
In this study, a simple method of biocathode fabrication in a Cr(VI)-reducing microbial fuel cell (MFC) is demonstrated. A self-assembling graphene was decorated onto the biocathode microbially, constructing a graphene/biofilm, in situ. The maximum power density of the MFC with a graphene biocathode is 5.7 times that of the MFC with a graphite felt biocathode. Cr(VI) reduction was also enhanced, resulting in 100% removal of Cr(VI) within 48h, at 40mg/L Cr(VI), compared with only 58.3% removal of Cr(VI) in the MFC with a graphite felt biocathode...
November 5, 2016: Journal of Hazardous Materials
Bo Sgum Wu, Judy Gopal, Pei-Yang Hua, Hui-Fen Wu
Detection is the first step to efficient treatment, therefore early detection of biofilm gains paramount importance for the initiation of mitigation protocols. A systematic study was conducted to detect the biofilm formation (1h to 2month period) on aluminium, titanium surfaces and their corresponding oxide film surfaces. The limit of detection (LOD) in case of traditional MALDI-MS was limited to a 6h old biofilm. Whereas, in case of the Graphene nanosheet mediated MALDI-MS (GN-MALDI-MS) approach, early detection of the biofilm was demonstrated to be 1h on titanium surfaces and 3h for Al surfaces...
September 1, 2016: Materials Science & Engineering. C, Materials for Biological Applications
François Perreault, Humberto Jaramillo, Ming Xie, Mercy Ude, Long D Nghiem, Menachem Elimelech
Forward osmosis (FO) is an emerging membrane process with potential applications in the treatment of highly fouling feedwaters. However, biofouling, the adhesion of microorganisms to the membrane and the subsequent formation of biofilms, remains a major limitation since antifouling membrane modifications offer limited protection against biofouling. In this study, we evaluated the use of graphene oxide (GO) for biofouling mitigation in FO. GO functionalization of thin-film composite membranes (GO-TFC) increased the surface hydrophilicity and imparted antimicrobial activity to the membrane without altering its transport properties...
June 7, 2016: Environmental Science & Technology
Mei Zhang, Yanhua Zhao, Li Yan, Raoul Peltier, Wenli Hui, Xi Yao, Yali Cui, Xianfeng Chen, Hongyan Sun, Zuankai Wang
Environmental biofouling caused by the formation of biofilm has been one of the most urgent global concerns. Silver nanoparticles (NPs), owing to their wide-spectrum antimicrobial property, have been widely explored to combat biofilm, but their extensive use has raised growing concern because they persist in the environment. Here we report a novel hybrid nanocomposite that imparts enhanced antimicrobial activity and low cytotoxicity yet with the advantage of reduced silver loading. The nanocomposite consists of Pt/Ag bimetallic NPs (BNPs) decorated on the porous reduced graphene oxide (rGO) nanosheets...
April 6, 2016: ACS Applied Materials & Interfaces
Naoko Yoshida, Yasushi Miyata, Kasumi Doi, Yuko Goto, Yuji Nagao, Ryugo Tero, Akira Hiraishi
Graphene oxide (GO) is reduced by certain exoelectrogenic bacteria, but its effects on bacterial growth and metabolism are a controversial issue. This study aimed to determine whether GO functions as the terminal electron acceptor to allow specific growth of and electricity production by exoelectrogenic bacteria. Cultivation of environmental samples with GO and acetate as the sole substrate could specifically enrich exoelectrogenic bacteria with Geobacter species predominating (51-68% of the total populations)...
2016: Scientific Reports
Zhiping Zeng, Dingshan Yu, Ziming He, Jing Liu, Fang-Xing Xiao, Yan Zhang, Rong Wang, Dibakar Bhattacharyya, Timothy Thatt Yang Tan
Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E...
2016: Scientific Reports
Hao Ren, He Tian, Cameron L Gardner, Tian-Ling Ren, Junseok Chae
A microbial fuel cell (MFC) is a bio-inspired renewable energy converter which directly converts biomass into electricity. This is accomplished via the unique extracellular electron transfer (EET) of a specific species of microbe called the exoelectrogen. Many studies have attempted to improve the power density of MFCs, yet the reported power density is still nearly two orders of magnitude lower than other power sources/converters. Such a low performance can primarily be attributed to two bottlenecks: (i) ineffective electron transfer from microbes located far from the anode and (ii) an insufficient buffer supply to the biofilm...
February 14, 2016: Nanoscale
Carolina Parra, Fernando Dorta, Edra Jimenez, Ricardo Henríquez, Cristian Ramírez, Rodrigo Rojas, Patricio Villalobos
BACKGROUND: Biofouling, the colonization of artificial and natural surfaces by unwanted microorganisms, has an important economic impact on a wide range of industries. Low cost antifouling strategies are typically based on biocides which exhibit a negative environmental impact, affecting surrounding organisms related and not related to biofouling. Considering that the critical processes resulting in biofouling occur in the nanoscale/microscale dimensions, in this work we present a bionanotechnological approach to reduce adhesion of biofilm-producing bacteria Halomonas spp...
2015: Journal of Nanobiotechnology
Nalenthiran Pugazhenthiran, Soujit Sen Gupta, Anupama Prabhath, Muthu Manikandan, Jakka Ravindran Swathy, V Kalyan Raman, Thalappil Pradeep
We describe a simple and inexpensive cellulose-derived and layer-by-layer stacked carbon fiber network electrode for capacitive deionization (CDI) of brackish water. The microstructure and chemical composition were characterized using spectroscopic and microscopic techniques; electrochemical/electrical performance was evaluated by cyclic voltammetry and 4-probe electrical conductivity and surface area by Brunauer-Emmett-Teller analysis, respectively. The desalination performance was investigated using a laboratory batch model CDI unit, under fixed applied voltage and varying salt concentrations...
September 16, 2015: ACS Applied Materials & Interfaces
Rui Yin, Tanupriya Agrawal, Usman Khan, Gaurav K Gupta, Vikrant Rai, Ying-Ying Huang, Michael R Hamblin
The relentless advance of drug-resistance among pathogenic microbes, mandates a search for alternative approaches that will not cause resistance. Photodynamic inactivation (PDI) involves the combination of nontoxic dyes with harmless visible light to produce reactive oxygen species that can selectively kill microbial cells. PDI can be broad-spectrum in nature and can also destroy microbial cells in biofilms. Many different kinds of nanoparticles have been studied to potentiate antimicrobial PDI by improving photosensitizer solubility, photochemistry, photophysics and targeting...
2015: Nanomedicine
He Jian-Zhou, Li Cheng-Cheng, Wang Deng-Jun, Dong-Mei Zhou
Understanding the fate and transport of graphene oxide nanoparticles (GONPs) in the subsurface environments is of crucial importance since they may pose potential risks to the environment and human health. However, little is known about the significance of biofilm on mobility of GONPs in the subsurface. Here we investigated the transport of GONPs in saturated sand coated with Bacillus subtilis (Gram-positive) and Pseudomonas putida (Gram-negative) biofilms, and their secreted extracellular polymeric substances (EPS) under environmentally relevant ionic strengths (1-50mM NaCl) at pH 7...
December 30, 2015: Journal of Hazardous Materials
Yi Jiang, Wei-Ning Wang, Di Liu, Yao Nie, Wenlu Li, Jiewei Wu, Fuzhong Zhang, Pratim Biswas, John D Fortner
In this work, we describe multifunctional, crumpled graphene oxide (CGO) porous nanocomposites that are assembled as advanced, reactive water treatment membranes. Crumpled 3D graphene oxide based materials fundamentally differ from 2D flat graphene oxide analogues in that they are highly aggregation and compression-resistant (i.e., π-π stacking resistant) and allow for the incorporation (wrapping) of other, multifunctional particles inside the 3D, composite structure. Here, assemblies of nanoscale, monomeric CGO with encapsulated (as a quasi core-shell structure) TiO2 (GOTI) and Ag (GOAg) nanoparticles, not only allow high water flux via vertically tortuous nanochannels (achieving water flux of 246 ± 11 L/(m(2)·h·bar) with 5...
June 2, 2015: Environmental Science & Technology
Sachin Kumar, Shammy Raj, Elayaraja Kolanthai, A K Sood, S Sampath, Kaushik Chatterjee
Toward designing the next generation of resorbable biomaterials for orthopedic applications, we studied poly(ε-caprolactone) (PCL) composites containing graphene. The role, if any, of the functionalization of graphene on mechanical properties, stem cell response, and biofilm formation was systematically evaluated. PCL composites of graphene oxide (GO), reduced GO (RGO), and amine-functionalized GO (AGO) were prepared at different filler contents (1%, 3%, and 5%). Although the addition of the nanoparticles to PCL markedly increased the storage modulus, this increase was largest for GO followed by AGO and RGO...
February 11, 2015: ACS Applied Materials & Interfaces
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