1
|
Saha DC, Boegel SJ, Tanvir S, Nogueira CL, Aucoin MG, Anderson WA, Jahed H. Antiviral and Antibacterial Cold Spray Coating Application on Rubber Substrate, Disruption in Disease Transmission Chain. J Therm Spray Technol 2023; 32:818-830. [PMID: 37521526 PMCID: PMC9911180 DOI: 10.1007/s11666-023-01553-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/22/2022] [Accepted: 01/24/2023] [Indexed: 08/01/2023]
Abstract
The objective of this study was to prepare a copper-coated rubber surface using cold spray technology with improved virucidal and antimicrobial properties to fight against highly transmissible viruses and bacteria. A successful cold spray coating was produced using irregular-shaped pure Cu powder on an escalator handrail rubber. The powder particles and the deposited coatings (single and double pass) were characterized in terms of particle morphology and size distribution, coating surface and coat/substrate cross-section properties. The bonding between powder and rubber surfaces was purely mechanical interlocking. The Cu powder penetration depth within the rubber surface increases with a number of depositions pass. The virucidal properties of the coated surface were tested utilizing surrogates for SARS-CoV-2: HCoV-229E, a seasonal human coronavirus, and baculovirus, a high-titer enveloped insect cell virus. A double-pass coated surface showed significant baculovirus inactivation relative to a bare rubber control surface after 2-h (approximately 1.7-log) and 4-h (approximately 6.2-log), while a 4-h exposure reduced HCoV-229E titer to below the limit of detection. A similar microbial test was performed using E. coli, showing a 4-log microbial reduction after 2-h exposure relative to the bare rubber. These promising results open a new application for cold spray in the health sector. Supplementary Information The online version contains supplementary material available at 10.1007/s11666-023-01553-x.
Collapse
Affiliation(s)
- D. C. Saha
- Fatigue and Stress Analysis Laboratory, Department of Mechanical & Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 Canada
| | - S. J. Boegel
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - S. Tanvir
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - C. L. Nogueira
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - M. G. Aucoin
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - W. A. Anderson
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - H. Jahed
- Fatigue and Stress Analysis Laboratory, Department of Mechanical & Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 Canada
| |
Collapse
|
2
|
Frey HC, Grieshop AP, Khlystov A, Bang JJ, Rouphail N, Guinness J, Rodriguez D, Fuentes M, Saha P, Brantley H, Snyder M, Tanvir S, Ko K, Noussi T, Delavarrafiee M, Singh S. Characterizing Determinants of Near-Road Ambient Air Quality for an Urban Intersection and a Freeway Site. Res Rep Health Eff Inst 2022; 2022:1-73. [PMID: 36314577 PMCID: PMC9620485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
INTRODUCTION Near-road ambient air pollution concentrations that are affected by vehicle emissions are typically characterized by substantial spatial variability with respect to distance from the roadway and temporal variability based on the time of day, day of week, and season. The goal of this work is to identify variables that explain either temporal or spatial variability based on case studies for a freeway site and an urban intersection site. The key hypothesis is that dispersion modeling of near-road pollutant concentrations could be improved by adding estimates or indices for site-specific explanatory variables, particularly related to traffic. Based on case studies for a freeway site and an urban intersection site, the specific aims of this project are to (1) develop and test regression models that explain variability in traffic-related air pollutant (TRAP) ambient concentration at two near-roadway locations; (2) develop and test refined proxies for land use, traffic, emissions and dispersion; and (3) prioritize inputs according to their ability to explain variability in ambient concentrations to help focus efforts for future data collection and model development. The key pollutants that are the key focus of this work include nitrogen oxides (NOx), carbon monoxide (CO), black carbon (BC), fine particulate matter (PM2.5; PM ≤ 2.5 μm in aerodynamic diameter), ultrafine particles (UFPs; PM ≤ 0.1 μm in aerodynamic diameter), and ozone (O3). NOx, CO, and BC are tracers of vehicle emissions and dispersion. PM2.5 is influenced by vehicle table emissions and regional sources. UFPs are sensitive to primary vehicle emissions. Secondary particles can form near roadways and on regional scales, influencing both PM2.5 and UFP concentrations. O3 concentrations are influenced by interaction with NOx near the roadway. Nitrogen dioxide (NO2), CO, PM2.5, and O3 are regulated under the National Ambient Air Quality Standards (NAAQS) because of demonstrated health effects. BC and UFPs are of concern for their potential health effects. Therefore, these pollutants are the focus of this work. METHODS The methodological approach includes case studies for which variables are identified and assesses their ability to explain either temporal or spatial variability in pollutant ambient concentrations. The case studies include one freeway location and one urban intersection. The case studies address (1) temporal variability at a fixed monitor 10 meters from a freeway; (2) downwind concentrations perpendicular to the same location; (3) variability in 24-hour average pollutant concentrations at five sites near an urban intersection; and (4) spatiotemporal variability along a walking path near that same intersection. The study boundary encompasses key factors in the continuum from vehicle emissions to near-road exposure concentrations. These factors include land use, transportation infrastructure and traffic control, vehicle mix, vehicle (traffic) flow, on-road emissions, meteorology, transport and evolution (transformation) of primary emissions, and production of secondary pollutants, and their resulting impact on measured concentrations in the near-road environment. We conducted field measurements of land use, traffic, vehicle emissions, and near-road ambient concentrations in the vicinity of two newly installed fixed-site monitors. One is a monitoring station jointly operated by the U.S. Environmental Protection Agency (U.S. EPA) and the North Carolina Department of Environmental Quality (NC DEQ) on I-40 between Airport Boulevard and I-540 in Wake County, North Carolina. The other is a fixed-site monitor for measuring PM2.5 at the North Carolina Central University (NCCU) campus on E. Lawson Street in Durham, North Carolina. We refer to these two locations as the freeway site and the urban site, respectively. We developed statistical models for the freeway and urban sites. RESULTS We quantified land use metrics at each site, such as distances to the nearest bus stop. For the freeway site, we quantified lane-by-lane total vehicle count, heavy vehicle (HV) count, and several vehicle-activity indices that account for distance from each lane to the roadside monitor. For the urban site, we quantified vehicle counts for all 12 turning movements through the intersection. At each site, we measured microscale vehicle tailpipe emissions using a portable emission measurement system. At the freeway site, we measured the spatial gradient of NOx, BC, UFPs, and PM, quantified particle size distributions at selected distances from the roadway and assessed partitioning of particles as a function of evolving volatility. We also quantified fleet-average emission factors for several pollutants. At the urban site, we measured daily average concentrations of nitric oxide (NO), NOx, O3, and PM2.5 at five sites surrounding the intersection of interest; we also measured high resolution (1-second to 10-second averages) concentrations of O3, PM2.5, and UFPs along a pedestrian transect. At both sites, the Research LINE-source (R-LINE) dispersion model was applied to predict concentration gradients based on the physical dispersion of pollution. Statistical models were developed for each site for selected pollutants. With variables for local wind direction, heavy-vehicle index, temperature, and day type, the multiple coefficient of determination (R2) was 0.61 for hourly NOx concentrations at the freeway site. An interaction effect of the dispersion model and a real-time traffic index contributed only 24% of the response variance for NOx at the freeway site. Local wind direction, measured near the road, was typically more important than wind direction measured some distance away, and vehicle-activity metrics directly related to actual real-time traffic were important. At the urban site, variability in pollutant concentrations measured for a pedestrian walk-along route was explained primarily by real-time traffic metrics, meteorology, time of day, season, and real-world vehicle tailpipe emissions, depending on the pollutant. The regression models explained most of the variance in measured concentrations for BC, PM, UFPs, NO, and NOx at the freeway site and for UFPs and O3 at the urban site pedestrian transect. CONCLUSIONS Among the set of candidate explanatory variables, typically only a few were needed to explain most of the variability in observed ambient concentrations. At the freeway site, the concentration gradients perpendicular to the road were influenced by dilution, season, time of day, and whether the pollutant underwent chemical or physical transformations. The explanatory variables that were useful in explaining temporal variability in measured ambient concentrations, as well as spatial variability at the urban site, were typically localized real-time traffic-volume indices and local wind direction. However, the specific set of useful explanatory variables was site, context (e.g., next to road, quadrants around an intersection, pedestrian transects), and pollutant specific. Among the most novel of the indicators, variability in real-time measured tailpipe exhaust emissions was found to help explain variability in pedestrian transect UFP concentrations. UFP particle counts were very sensitive to real-time traffic indicators at both the freeway and urban sites. Localized site-specific data on traffic and meteorology contributed to explaining variability in ambient concentrations. HV traffic influenced near-road air quality at the freeway site more so than at the urban site. The statistical models typically explained most of the observed variability but were relatively simple. The results here are site-specific and not generalizable, but they are illustrative that near-road air quality can be highly sensitive to localized real-time indicators of traffic and meteorology.
Collapse
Affiliation(s)
| | | | | | - J J Bang
- North Carolina Central University
| | | | | | | | | | - P Saha
- North Carolina State University
| | | | - M Snyder
- University of North Carolina, Chapel Hill
| | | | - K Ko
- North Carolina State University
| | - T Noussi
- North Carolina Central University
| | | | - S Singh
- North Carolina State University
| |
Collapse
|
3
|
Aithal S, Mishriki S, Gupta R, Sahu RP, Botos G, Tanvir S, Hanson RW, Puri IK. SARS-CoV-2 detection with aptamer-functionalized gold nanoparticles. Talanta 2022; 236:122841. [PMID: 34635231 PMCID: PMC8409056 DOI: 10.1016/j.talanta.2021.122841] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 12/15/2022]
Abstract
A rapid detection test for SARS-CoV-2 is urgently required to monitor virus spread and containment. Here, we describe a test that uses nanoprobes, which are gold nanoparticles functionalized with an aptamer specific to the spike membrane protein of SARS-CoV-2. An enzyme-linked immunosorbent assay confirms aptamer binding with the spike protein on gold surfaces. Protein recognition occurs by adding a coagulant, where nanoprobes with no bound protein agglomerate while those with sufficient bound protein do not. Using plasmon absorbance spectra, the nanoprobes detect 16 nM and higher concentrations of spike protein in phosphate-buffered saline. The time-varying light absorbance is examined at 540 nm to determine the critical coagulant concentration required to agglomerates the nanoprobes, which depends on the protein concentration. This approach detects 3540 genome copies/μl of inactivated SARS-CoV-2.
Collapse
Affiliation(s)
- Srivatsa Aithal
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Sarah Mishriki
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Rohit Gupta
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Rakesh P Sahu
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada; School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada
| | - George Botos
- Genemis Laboratories, Cambridge, Ontario, Canada; Aptavid, New York, USA
| | | | | | - Ishwar K Puri
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada; School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
4
|
Kaur A, Anderson WA, Tanvir S, Kansal SK. Solar light active silver/iron oxide/zinc oxide heterostructure for photodegradation of ciprofloxacin, transformation products and antibacterial activity. J Colloid Interface Sci 2019; 557:236-253. [PMID: 31521973 DOI: 10.1016/j.jcis.2019.09.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 02/07/2023]
Abstract
This paper reports on the multitasking potential of a silver/iron oxide/zinc oxide (Ag/Fe2O3/ZnO) heterostructure, which was used for the photocatalytic decomposition of ciprofloxacin (CPX) and bacterial disinfection. The Ag/Fe2O3/ZnO heterostructure was successfully prepared using a facile precipitation method, and characterization results showed interesting structural, morphological, compositional and luminescent properties. The morphological results of the prepared heterostructure confirmed the deposition of Ag nanoparticles onto the surface of ZnO nanoplates and Fe2O3 nanorods. Treatment studies showed that the Ag/Fe2O3/ZnO heterostructure had superior solar light driven photocatalytic activity towards CPX degradation (76.4%) compared to bare Fe2O3 nanorods (43.2%) and ZnO nanoplates (63.1%), Ag/Fe2O3 (28.2%) and Ag/ZnO (64.5%) under optimized conditions (initial CPX concentration: 10 mg/L; pH 4; catalyst loading: 0.3 g/L). Reactive species study confirmed the roles of e-, h+, OH and O2- in the photocatalytic degradation process. This photocatalytic behaviour of the Ag/Fe2O3/ZnO heterostructure could be attributed to the improved full solar spectrum harvesting capacity, separation of charge carriers and migration of e-/h+ across the heterostructure interface. In addition, the Ag/Fe2O3/ZnO heterostructure also showed good antibacterial activity against Escherichia coli (E. coli) under both dark and visible light conditions. This might be due to generation of reactive oxygen species during the reaction. To the best of our knowledge, this is the first study till date on the utilization of Ag/Fe2O3/ZnO heterostructure for the photocatalytic degradation of CPX and E. coli bacteria disinfection. Therefore, this work offers an attractive path to design ZnO-based ternary heterostructures for solar-driven applications in wastewater remediation.
Collapse
Affiliation(s)
- Amandeep Kaur
- Dr. S. S. Bhatnagar University Institute of Chemical Engineering and Technology, Panjab University, Chandigarh 160014, India
| | - William A Anderson
- Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Shazia Tanvir
- Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Sushil Kumar Kansal
- Dr. S. S. Bhatnagar University Institute of Chemical Engineering and Technology, Panjab University, Chandigarh 160014, India.
| |
Collapse
|
5
|
Tanvir S, Sajjad S, Roshan R. Awareness levels of prevention of cardiac diseases in general population of rawalpindi and requirement of health education. Public Health 2018; 157:107-110. [PMID: 29505914 DOI: 10.1016/j.puhe.2018.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/06/2018] [Accepted: 01/10/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To assess the level of awareness in population about cardiac diseases prevention and suggestion of recommendations. STUDY DESIGN Descriptive cross-sectional survey was carried out in Rawalpindi Cantonment in Oct 2016. METHODS 100 respondents were selected through convenience sampling. Data was collected through questionnaire. RESULTS Results indicated low levels of awareness as only 30% of the population knew that cardiac diseases can be prevented to certain extent by lifestyle changes. 46% population knew about importance of physical activity and 34% knew that excess of fried and salty food can cause cardiac diseases. Only 22% population knew that red meat use in excess can cause cardiac diseases. 20% population were aware that lack of sleep can cause cardiac disease. 13% (for sodas), 15% (for sweets) 13% (for consuming egg yolk daily) and 28% (for stress) were the statistics for remaining modifiable risk factors. 80% of the population was aware of smoking hazards which shows the success of anti-smoking campaigns. CONCLUSION These levels of awareness indicate that there is dire need of policy making for health education to make people aware of lifestyle modifications necessary to prevent cardiac diseases.
Collapse
Affiliation(s)
- S Tanvir
- Armed Forces Postgraduate Medical Institute, Rawalpindi, Pakistan
| | - S Sajjad
- Islamabad Institute of Dental Education & Allied Sciences, Islamabad Medical & Dental College, Islamabad, Pakistan.
| | - R Roshan
- Department of Public Health, Armed Forces Postgraduate Medical Institute, Rawalpindi, Pakistan
| |
Collapse
|
6
|
Tanvir F, Yaqub A, Tanvir S, Anderson WA. Poly-L-arginine Coated Silver Nanoprisms and Their Anti-Bacterial Properties. Nanomaterials (Basel) 2017; 7:E296. [PMID: 28953233 PMCID: PMC5666461 DOI: 10.3390/nano7100296] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/13/2017] [Accepted: 09/22/2017] [Indexed: 01/28/2023]
Abstract
The aim of this study was to test the effect of two different morphologies of silver nanoparticles, spheres, and prisms, on their antibacterial properties when coated with poly-L-arginine (poly-Arg) to enhance the interactions with cells. Silver nanoparticle solutions were characterized by UV-visible spectroscopy, transmission electron microscopy, dynamic light scattering, zeta potential, as well as antimicrobial tests. These ultimately showed that a prismatic morphology exhibited stronger antimicrobial effects against Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. The minimum bactericidal concentration was found to be 0.65 μg/mL in the case of a prismatic AgNP-poly-Arg-PVP (silver nanoparticle-poly-L-arginine-polyvinylpyrrolidone) nanocomposite. The anticancer cell activity of the silver nanoparticles was also studied, where the maximum effect against a HeLa cell line was 80% mortality with a prismatic AgNP-poly-Arg-PVP nanocomposite at a concentration of 11 μg/mL. The antimicrobial activity of these silver nanocomposites demonstrates the potential of such coated silver nanoparticles in the area of nano-medicine.
Collapse
Affiliation(s)
- Fouzia Tanvir
- Department of Zoology, Government College University, Lahore 54000, Pakistan.
| | - Atif Yaqub
- Department of Zoology, Government College University, Lahore 54000, Pakistan.
| | - Shazia Tanvir
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
| | - William A Anderson
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
| |
Collapse
|
7
|
Tanvir S, Thuróczy G, Selmaoui B, Silva Pires Antonietti V, Sonnet P, Arnaud-Cormos D, Lévêque P, Pulvin S, de Seze R. Effects of 3G cell phone exposure on the structure and function of the human cytochrome P450 reductase. Bioelectrochemistry 2016; 111:62-9. [PMID: 27243445 DOI: 10.1016/j.bioelechem.2016.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 05/10/2016] [Accepted: 05/10/2016] [Indexed: 11/29/2022]
Abstract
Cell phones increase exposure to radiofrequency (RF) electromagnetic fields (EMFs). Whether EMFs exert specific effects on biological systems remains debatable. This study investigated the effect of cell phone exposure on the structure and function of human NADPH-cytochrome P450 reductase (CPR). CPR plays a key role in the electron transfer to cytochrome P450, which takes part in a wide range of oxidative metabolic reactions in various organisms from microbes to humans. Human CPR was exposed for 60min to 1966-MHz RF inside a transverse electromagnetic cell (TEM-cell) placed in an incubator. The specific absorption rate (SAR) was 5W·kg(-1). Conformation changes have been detected through fluorescent spectroscopy of flavin and tryptophan residues, and investigated through circular dichroism, dynamic light scattering and microelectrophoresis. These showed that CPR was narrowed. By using cytochrome C reductase activity to assess the electron flux through the CPR, the Michaelis Menten constant (Km) and the maximum initial velocity (Vmax) decreased by 22% as compared with controls. This change was due to small changes in the tertiary and secondary structures of the protein at 37°C. The relevance of these findings to an actual RF exposure scenario demands further biochemical and in-vivo confirmation.
Collapse
Affiliation(s)
- Shazia Tanvir
- Sorbonne Universités, Université de Technologie de Compiègne, Laboratoire de Génie Enzymatique et Cellulaire, FRE CNRS 3580, CS60319, 60203 Compiègne Cedex. France
| | - György Thuróczy
- Unité de toxicologie expérimentale TOXI-PériTox UMR-I 01, Institut National de l'Environnement Industriel et des RISques (INERIS), Parc ALATA BP2, 60 550, Verneuil-en-Halatte, France; PériTOX, UPJV, Faculté de Médecine, 80 000 Amiens, France
| | - Brahim Selmaoui
- Unité de toxicologie expérimentale TOXI-PériTox UMR-I 01, Institut National de l'Environnement Industriel et des RISques (INERIS), Parc ALATA BP2, 60 550, Verneuil-en-Halatte, France; PériTOX, UPJV, Faculté de Médecine, 80 000 Amiens, France
| | - Viviane Silva Pires Antonietti
- Université de Picardie Jules Verne, Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources, UMR CNRS 7378, UFR de Pharmacie, 80 037, Amiens, France
| | - Pascal Sonnet
- Université de Picardie Jules Verne, Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources, UMR CNRS 7378, UFR de Pharmacie, 80 037, Amiens, France
| | | | - Philippe Lévêque
- Université de Limoges, CNRS, XLIM, UMR 7252, F-87000, Limoges, France
| | - Sylviane Pulvin
- Sorbonne Universités, Université de Technologie de Compiègne, Laboratoire de Génie Enzymatique et Cellulaire, FRE CNRS 3580, CS60319, 60203 Compiègne Cedex. France
| | - René de Seze
- Unité de toxicologie expérimentale TOXI-PériTox UMR-I 01, Institut National de l'Environnement Industriel et des RISques (INERIS), Parc ALATA BP2, 60 550, Verneuil-en-Halatte, France; PériTOX, UPJV, Faculté de Médecine, 80 000 Amiens, France.
| |
Collapse
|
8
|
Shi Z, Tang J, Chen L, Yan C, Tanvir S, Anderson WA, Berry RM, Tam KC. Enhanced colloidal stability and antibacterial performance of silver nanoparticles/cellulose nanocrystal hybrids. J Mater Chem B 2015; 3:603-611. [DOI: 10.1039/c4tb01647e] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Preparation of polydopamine functionalized CNCs and silver nanoparticle immobilized CNCs.
Collapse
Affiliation(s)
- Zengqian Shi
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | - Juntao Tang
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | - Li Chen
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | - Chuanren Yan
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | - Shazia Tanvir
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | - William A. Anderson
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| | | | - Kam C. Tam
- Department of Chemical Engineering
- Waterloo Institute for Nanotechnology
- University of Waterloo
- 200 University Ave. W
- Waterloo
| |
Collapse
|
9
|
Tanvir S, Oudet F, Pulvin S, Anderson WA. Coenzyme based synthesis of silver nanocrystals. Enzyme Microb Technol 2012; 51:231-6. [PMID: 22883558 DOI: 10.1016/j.enzmictec.2012.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 06/30/2012] [Accepted: 07/03/2012] [Indexed: 12/21/2022]
Abstract
In this work we have carried out systematic studies to identify the critical role of a coenzyme (β-NADPH) to synthesize silver nanoparticle. Interestingly, both roles of reducing and stabilizing agents are played by β-NADPH. Nanoparticles obtained by this route exhibit a good crystallinity, a narrow size distribution and excellent stability in aqueous solution. The most advantageous points of this single-step environmentally friendly approach are that it takes place at nearly room temperature (20 °C), overcomes many limitations encountered in other biological methods (such as the restricted concentration of AgNO₃, maintenance and manipulation of microorganisms, preparing extracts and contamination from residual reactants), bypasses the use of surfactants or capping agents and does not necessitate pH adjustment. The nano-Ag were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, UV-vis, and energy-dispersive X-ray spectroscopy (EDX). DLS, TEM and XRD measurements showed the formation of nano-Ag with an average diameter of 20.77±0.67 nm. XRD studies confirmed the nanocrystalline nature of the silver particles. Zeta potential measurements revealed that the particles are surrounded with negatively charged groups (-41±5 mV) making them stable in an aqueous medium. The EDX spectrum of the silver nanoparticles confirmed the presence of elemental silver signal in high percentage. In addition to the easy and ecofriendly method of synthesis, β-NADPH can be regenerated by enzymatic means through glucose 6-phosphate dehydrogenase, potentially making the synthesis more cost effective.
Collapse
Affiliation(s)
- Shazia Tanvir
- Laboratoire de Génie Enzymatique et Cellulaire, UMR 6022 CNRS, Université de Technologie de Compiègne, BP 20529-60205 Compiègne Cedex, France.
| | | | | | | |
Collapse
|
10
|
Tanvir S, Merlier F, Pulvin S. Biosensing of reactive intermediates produced by the photocatalytic activities of titanium dioxide nanoparticles. J Photochem Photobiol B 2012; 110:22-7. [PMID: 22417814 DOI: 10.1016/j.jphotobiol.2012.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 01/16/2012] [Accepted: 02/14/2012] [Indexed: 10/28/2022]
Abstract
The development of an enzyme based biosensing method is described for evaluating the toxicity of solutions treated by titanium dioxide photocatalysis. The method is based on the potential of rat liver microsomal glutathione transferase ability (mGST) to get enhanced in the conditions of chemical and oxidative toxicity. Phenol is taken as a model pollutant due to its toxicity and prevalence in industrial processes. Chemical analysis of the parent compound, products and acute toxicity assays using the mGST activity, were conducted during and after the various photocatalytic treatments. The maximum mGST activity was observed from 60 and 120 min treated samples. This post-treatment toxicity might be due to toxic phenolic products, which may include p-benzoquinone, hydroquinone, benzenetriol and other intermediates. The enzymatic activity pattern observed after photocatalytic treatment corresponded well with the chemical degradation data obtained by HPLC-UV. The mGST assay seems to be an easy to use and promising approach for evaluating the effectiveness of wastewater treatment processes.
Collapse
Affiliation(s)
- Shazia Tanvir
- Laboratoire de Génie Enzymatique et Cellulaire, UMR 6022 CNRS, Université de Technologie de Compiègne, BP 20529-60205 Compiègne Cedex, France.
| | | | | |
Collapse
|
11
|
Tanvir S, Morandat S, Frederic N, Adenier H, Pulvin S. Activity of immobilised rat hepatic microsomal CYP2E1 using alumina membrane as a support. N Biotechnol 2009; 26:222-8. [DOI: 10.1016/j.nbt.2009.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 08/03/2009] [Accepted: 08/16/2009] [Indexed: 11/24/2022]
|
12
|
Tanvir S, Adenier H, Pulvin S. Screening and prediction of reactive intermediates in a microreactor with immobilized rat hepatic microsomes using acetaminophen as a model drug. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2009.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Tanvir S, Pantigny J, Morandat S, Pulvin S. Development of immobilization technique for liver microsomes. Colloids Surf B Biointerfaces 2009; 68:178-83. [DOI: 10.1016/j.colsurfb.2008.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 09/24/2008] [Accepted: 10/01/2008] [Indexed: 11/27/2022]
|
14
|
Abstract
Though many microorganisms that are capable of using phenol as sole source of carbon have been isolated and characterized, only a few organisms degrading substituted phenols have been described to date. In this study, one strain of microorganism that is capable of using phenol (3,000 ppm), 4-aminophenol (4,000 ppm) and 4-acetamidophenol (4,000 ppm) as sole source of carbon and energy was isolated and characterized. This strain was obtained by enrichment culture from a site contaminated with compounds like 4-acetamidophenol, 4-aminophenol and phenol in Pakistan at Bhai Pheru. The contaminated site is able to support large bacterial community as indicated by the viable cell counts (2 x 10(4) - 5 x 10(8)) per gram of soil. Detailed taxonomic studies identified the organisms as Pseudomonas species designated as strain STI. The isolate also showed growth on other organic compounds like aniline, benzene, benzyl alcohol, benzyl bromide, toluene, p-cresol, trichloroethylene and o-xylene. Optimum growth temperature and pH were found to be 30 degrees C and 7, respectively, while growth at 4, 25 and 35 degrees C and at pH 8 and 9 was also observed. Non growing suspended cells of strain ST1 degraded 68, 96 and 76.8% of 4-aminophenol (1,000 ppm), phenol (500 ppm) and 4-acetamidophenol (1,000 ppm), respectively, in 72 hrs. The isolation and characterization of Pseudomonas species strain STI, may contribute to efforts on phenolic bioremediation, particularly in an environment with very high levels of 4-acetamidophenol and 4-aminophenol.
Collapse
Affiliation(s)
- S Ahmed
- Department of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | | | | | | |
Collapse
|