1
|
Jafari B, Botte GG. Reduced Graphene Oxide-Coated Fabrics for Joule-Heating and Antibacterial Applications. ACS APPLIED NANO MATERIALS 2023; 6:20006-20017. [PMID: 37969783 PMCID: PMC10644289 DOI: 10.1021/acsanm.3c03825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/27/2023] [Indexed: 11/17/2023]
Abstract
Multifunctional textiles have emerged as a significant area of research due to their growing importance and diverse applications. The main requirement for these fabrics is electroconductivity, which is usually gained by incorporating conductive materials such as graphene into the textile structure. In this article, an electrochemical method was demonstrated to integrate different loadings of reduced graphene oxide (rGO) into fabrics for enhanced electrical conductivity. The process involves spray coating of graphene oxide (GO) onto the fabric, followed by in situ electrochemical reduction of GO, resulting in a coating layer of rGO nanosheets. The rGO-coated fabric exhibited exceptional Joule-heating capabilities, achieving 127 °C under a 9 V direct voltage with only 770 μg/cm2 of rGO loading. Moreover, the antibacterial properties of the rGO-coated fabric were demonstrated, showing a significant reduction rate of over 99.99% against both Bacillus subtilis and Escherichia coli. Joule-heating and antibacterial performances of the rGO-coated fabric were investigated over eight repeated cycles, demonstrating excellent repeatability. The simplicity of the fabrication method, along with the electrothermal and antibacterial effects of the rGO-coated fabric, makes it a promising material for various practical applications.
Collapse
Affiliation(s)
- Behnaz Jafari
- Institute for Sustainability
and Circular Economy, Chemical and Electrochemical Technology and
Innovation Laboratory, Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79401, United States
| | - Gerardine G. Botte
- Institute for Sustainability
and Circular Economy, Chemical and Electrochemical Technology and
Innovation Laboratory, Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79401, United States
| |
Collapse
|
2
|
Lee JH, Yoo H, Ahn YJ, Kim HJ, Kwon SR. Evaluation of the Antimicrobial Effect of Graphene Oxide Fiber on Fish Bacteria for Application in Aquaculture Systems. MATERIALS (BASEL, SWITZERLAND) 2022; 15:966. [PMID: 35160912 PMCID: PMC8840572 DOI: 10.3390/ma15030966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/06/2022] [Accepted: 01/18/2022] [Indexed: 02/06/2023]
Abstract
The growing importance of the domestic aquaculture industry has led not only to its continuous development and expansion but also to an increase in the production of wastewater containing pathogenic microorganisms and antibiotic-resistant bacteria. As the existing water purification facilities have a high initial cost of construction, operation, and maintenance, it is necessary to develop an economical solution. Graphene oxide (GO) is a carbon-based nanomaterial that is easy to manufacture, inexpensive and has excellent antimicrobial properties. In this study, the antimicrobial effect of GO polyester fibers on seven species of fish pathogenic bacteria was analyzed to evaluate their effectiveness in water treatment systems and related products. As a result of incubating GO polyester fibers with seven types of fish pathogenic bacteria for 1, 6, and 12 h, there was no antimicrobial effect in Vibrio harveyi, V. scopthalmi, and Edwardsiella tarda. In contrast, GO fibers showed antimicrobial effects of more than 99% against A. hydrophila, S. parauberis, S. iniae, and P. piscicola, suggesting the potential use of GO fibers in water treatment systems.
Collapse
Affiliation(s)
- Ji Hyun Lee
- Department of Aquatic Life Medical Sciences, Sunmoon University, Asan 31460, Korea;
| | | | - Yu Jin Ahn
- SamhwanTF, Nowon-gu, Seoul 10848, Korea;
| | - Hyoung Jun Kim
- OIE Reference Laboratory for VHS, National Institute of Fisheries Science, Busan 46083, Korea
| | - Se Ryun Kwon
- Department of Aquatic Life Medical Sciences, Sunmoon University, Asan 31460, Korea;
- Genome-Based BioIT Convergence Institute, Asan 31460, Korea
| |
Collapse
|
3
|
Hernández-Gordillo A, Arriaga S. Mesoporous TiO 2 Monoliths Impregnated with CdS and CuO Nanoparticles for Airborne Bacteria Inactivation Under Visible Light. Catal Letters 2021; 152:629-640. [PMID: 34054251 PMCID: PMC8141277 DOI: 10.1007/s10562-021-03659-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/10/2021] [Indexed: 11/26/2022]
Abstract
In this work, macroscopic TiO2 monoliths are proposed to serve simultaneously as support and co-catalyst in a continuous flow photoreactor. The impregnation via one-pot of mesoporous TiO2 with CdS (m-TiO2/CdS) and CuO (m-TiO2/CuO) nanoparticles enabled the formation of photocatalytic heterojunctions retaining high specific surface area (~ 100 m2/g). The impregnated monoliths of 2-3 mm in size were employed as photocatalysts to inactivate airborne bacteria under blue light, reducing the emission of living airborne bacteria up to 0.1% and 37.7% when using m-TiO2/CdS and m-TiO2/CuO, respectively. Bacteria were characterized and quantified by flow cytometry and cell lysis was confirmed by SEM, detecting collapsed bacteria. Along 96 h of continuous photocatalysis at a flow rate of 2.2 L/min, the cell concentration presented maxima and minima due to the adsorption-desorption stages of bioaerosols over the catalysts, in concordance with thermal gravimetric analysis. The reactivation of catalysts was achieved by calcination at 400 °C, however, after a third re-cycle, the photocatalytic activity for all monoliths was practically negligible because the physicochemical surface changes hinder the adequate bioaerosol adsorption. These porous systems could emerge as promising gas-phase catalysts since the mass transport is facilitated by porosity and the release of catalyst nanoparticles is avoided by the active support, providing a safe and viable model for bioaerosols inactivation to improve indoor air quality with the use of interior lighting. Supplementary Information The online version contains supplementary material available at 10.1007/s10562-021-03659-9.
Collapse
Affiliation(s)
- Armin Hernández-Gordillo
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, 78216 San Luis Potosí, México
| | - Sonia Arriaga
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, 78216 San Luis Potosí, México
| |
Collapse
|
4
|
Fully integrated optofluidic SERS platform for real-time and continuous characterization of airborne microorganisms. Biosens Bioelectron 2020; 169:112611. [DOI: 10.1016/j.bios.2020.112611] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 09/01/2020] [Accepted: 09/12/2020] [Indexed: 01/21/2023]
|
5
|
Matharu RK, Tabish TA, Trakoolwilaiwan T, Mansfield J, Moger J, Wu T, Lourenço C, Chen B, Ciric L, Parkin IP, Edirisinghe M. Microstructure and antibacterial efficacy of graphene oxide nanocomposite fibres. J Colloid Interface Sci 2020; 571:239-252. [DOI: 10.1016/j.jcis.2020.03.037] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/08/2020] [Accepted: 03/09/2020] [Indexed: 01/10/2023]
|
6
|
Abstract
Biomass combustion is known to be one of the main contributors to air pollution. However, the influence of biomass burning on the distribution of viable bacterial and fungal aerosols is uncertain. This study aimed to examine survivability of bacteria and fungi in the post-combustion products, and to investigate the aerosolization of viable cells during combustion of different types of organic materials. Laboratory experiments included a small-scale combustion of organic materials contaminated with microorganisms in order to determine the survivability of microbes in the combustion products and the potential aerosolization of viable cells during combustion. Field experiments were completed during intentional and prescribed biomass burning events in order to investigate the aerosolization mechanisms that are not available at the laboratory scale. Laboratory experiments did not demonstrate aerosolization of microorganisms during biomass combustion. However, the relatively high survival rate of bacteria in the combustion products ought to be accounted for, as the surviving microorganisms can potentially be aerosolized by high velocity natural air flows. Field investigations demonstrated significant increase in the bioaerosol concentration above natural background during and after biomass combustion.
Collapse
|
7
|
Cho YS, Kim HR, Ko HS, Jeong SB, Chan Kim B, Jung JH. Continuous Surveillance of Bioaerosols On-Site Using an Automated Bioaerosol-Monitoring System. ACS Sens 2020; 5:395-403. [PMID: 31913022 DOI: 10.1021/acssensors.9b02001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Real-time on-site monitoring of bioaerosols in an air environment is important for preventing various adverse health effects including respiratory diseases and allergies caused by bioaerosols. Here, we report the development of an on-site automated bioaerosol-monitoring system (ABMS) using integrated units including a wet-cyclone bioaerosol sampler, a thermal-lysis unit for extracting adenosine triphosphate (ATP), an ATP-detection unit based on the immobilization of luciferase/luciferin for bioluminescence reactions, and a photomultiplier tube-based detector. The performance of the bioaerosol detection system was verified using Escherichia coli (E. coli) as a model source. Each unit was optimized to process ∼9.6 × 105 times the concentrated ratio of collected bioaerosol samples, using a 3 min lysis time to extract ATP, and has a detection limit of ∼375 colony-forming units (CFUs)/mL with more than 30 days of stability for the immobilized-luciferase/luciferin detection unit supported by a glass-fiber conjugation pad. After the integration of all units, the ABMS achieved E. coli bioaerosol monitoring with continuous detection at 5 min intervals and a minimum detection limit of ∼130 CFU/mair3. Furthermore, the rapid responsivity and stable operation performance of the ABMS under test-bed conditions and during a field test demonstrated that the ABMS is capable of continuously monitoring bioaerosols in real-time with high sensitivity. The monitoring system developed here with immobilization strategies for bioluminescence reactions triggered by ATP extracted from collected bioaerosol samples using a simple heat-lysis method may help establish sustainable platforms to obtain stable signals for the real-time detection of bioaerosols on-site.
Collapse
Affiliation(s)
- Yu Sung Cho
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Graduate School of Energy and Environment, Korea University, Seoul 02841, Republic of Korea
| | - Hye Ri Kim
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Division of Energy & Environment Technology, KIST School, University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Hyun Sik Ko
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Graduate School of Energy and Environment, Korea University, Seoul 02841, Republic of Korea
| | - Sang Bin Jeong
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Graduate School of Energy and Environment, Korea University, Seoul 02841, Republic of Korea
| | - Byoung Chan Kim
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Division of Energy & Environment Technology, KIST School, University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Jae Hee Jung
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Graduate School of Energy and Environment, Korea University, Seoul 02841, Republic of Korea
- Division of Energy & Environment Technology, KIST School, University of Science and Technology (UST), Seoul 02792, Republic of Korea
| |
Collapse
|
8
|
Wang C, Hu X, Zhang Z. Airborne disinfection using microwave-based technology: Energy efficient and distinct inactivation mechanism compared with waterborne disinfection. JOURNAL OF AEROSOL SCIENCE 2019; 137:105437. [PMID: 32226120 PMCID: PMC7094417 DOI: 10.1016/j.jaerosci.2019.105437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 06/03/2023]
Abstract
Microwave has been extensively applied to inactivate microorganisms in liquids, food, and surfaces. However, energy efficiency is a limiting factor for the environmental application. The utilization pathway and energy efficiency of the microwave in different media have not been investigated. In this study, the inactivation performance, energy utilization, and bactericidal mechanisms for microwave-irradiated airborne and waterborne Escherichia coli were compared. A Beer-Lambert law-based model was also developed and validated to compare the inactivation performance in different phases. Microwave had greater inactivation effect on airborne bacteria than waterborne bacteria. The inactivation rate constant for airborne E. coli (0.29 s-1) was nearly 20 times higher than that of waterborne species (0.014 s-1). Most of the absorbed microwave energy (92.3%) was converted to increase water temperature instead of inactivating the waterborne bacteria, because the microwave photons were easily absorbed by water molecules. By contrast, 45.4% of the absorbed energy could disinfect the airborne bacteria. Finally, the required energies for 1-log inactivation were calculated as 2.3 J and 116.9 J per log-inactivation for airborne and waterborne E. coli, respectively. The airborne and waterborne E. coli samples showed distinct microwave inactivation mechanisms. Waterborne E. coli disinfection was primarily due to thermal effect, while the non-thermal effect was the major mechanism for airborne E. coli inactivation.
Collapse
Affiliation(s)
- Can Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
- Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300350, PR China
| | - Xurui Hu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
- Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300350, PR China
| | - Zhiwei Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
- Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300350, PR China
| |
Collapse
|
9
|
Souzandeh H, Wang Y, Netravali AN, Zhong WH. Towards Sustainable and Multifunctional Air-Filters: A Review on Biopolymer-Based Filtration Materials. POLYM REV 2019. [DOI: 10.1080/15583724.2019.1599391] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Hamid Souzandeh
- Fiber Science and Apparel Design, Cornell University, Ithaca, New York, USA
| | - Yu Wang
- School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington, USA
| | - Anil N. Netravali
- Fiber Science and Apparel Design, Cornell University, Ithaca, New York, USA
| | - Wei-Hong Zhong
- School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington, USA
| |
Collapse
|
10
|
Fang Z, Guo W, Zhang J, Lou X. Influence of Heat Events on the Composition of Airborne Bacterial Communities in Urban Ecosystems. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E2295. [PMID: 30347662 PMCID: PMC6210276 DOI: 10.3390/ijerph15102295] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/19/2018] [Accepted: 10/01/2018] [Indexed: 12/14/2022]
Abstract
Airborne bacteria are significantly affected by meteorological and environmental conditions. However, there is little quantitative data available on the effects of these factors on airborne bacteria in urban ecosystems. In the present study, we analyzed weather-dependent changes in the composition of airborne bacterial communities using high throughput sequencing. Samples were collected before and after a period of constant hot weather at four selected sampling sites (YRBS, ZJGUSJC, TJCR, and BLQG) in Hangzhou. Our results show that the average amount of bacterial 16S rRNA gene copy numbers per m³ of air decreased significantly after constant high temperature. In addition, the number of operational taxonomic units and the Shannon⁻Wiener diversity indexes of the samples at all four selected sampling sites were significantly decreased after the heat event, showing notable impact on bacterial diversity. We also detected a significant increase in the abundances of spore-forming bacteria. Firmicutes increased from 3.7% to 9.9%, Bacillales increased from 2.6% to 7.6%, and Bacillaceae increased from 1.5% to 5.9%. In addition, we observed an increase in beta-Proteobacteria (18.2% to 50.3%), Rhodocyclaceae (6.9% to 29.9%), and Burkholderiaceae (8.1% to 15.2%). On the other hand, the abundance of alpha-Proteobacteria (39.6% to 9.8%), Caulobacteraceae (17.9% to 0.5%), Sphingomonadaceae (7.2% to 3.3%), and Xanthomonadaceae (3.0% to 0.5%) was significantly lower. Taken together, our data suggest that the composition of airborne bacterial communities varies greatly dependent on heat events, and that such communities include several species that are highly susceptible to high-temperature related stressors such as high air temperature, low relative humidity, and high intensity of solar radiation.
Collapse
Affiliation(s)
- Zhiguo Fang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China.
| | - Weijun Guo
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China.
| | - Junwen Zhang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China.
| | - Xiuqin Lou
- Hangzhou Center for Disease Control and Prevention, Hangzhou 310021, China.
| |
Collapse
|
11
|
Hyun J, Lee SG, Hwang J. Application of corona discharge-generated air ions for filtration of aerosolized virus and inactivation of filtered virus. JOURNAL OF AEROSOL SCIENCE 2017; 107:31-40. [PMID: 32226115 PMCID: PMC7094352 DOI: 10.1016/j.jaerosci.2017.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/07/2016] [Accepted: 02/09/2017] [Indexed: 05/19/2023]
Abstract
The effect of corona discharge-generated air ions on the filtration of aerosolized bacteriophage MS2 was studied. A carbon-fiber ionizer was installed upstream of a medium-efficiency air filter to generate air ions, which were used to charge the virus aerosols and increase their filtration efficiency. After the virus aerosols were captured by the filter for a certain time interval, they were exposed to a newly incoming air ion flow. Captured virus particles were detached from the filter by sonication, and their antiviral efficiency due to air ions was calculated by counting the plaque-forming units. The antiviral efficiency increased with ion exposure time and ion concentration. When the concentration of positive air ions was 107 ions/cm3, the antiviral efficiencies were 46.1, 78.8, and 83.7% with exposure times of 15, 30, and 45 min, respectively. When the ionizer was operated in a bipolar mode, the number concentrations of positive and negative ions were 6.6×106 and 3.4×106 ions/cm3, respectively, and the antiviral efficiencies were 64.3, 89.1, and 97.4% with exposure times of 15, 30, and 45 min, respectively. As a quantitative parameter for the performance evaluation of air ions, the susceptibility constant of bacteriophage MS2 to positive, negative, bipolar air ions was calculated as 5.5×10-3, 5.4×10-3 and 9.5×10-3, respectively. These susceptibility constants showed bipolar ion treatment was more effective about 1.7 times than unipolar ion treatment.
Collapse
Affiliation(s)
- Junho Hyun
- Graduate Programs in Clean Technology, Yonsei University, Seoul 03722, Korea
| | - Sang-Gu Lee
- Graduate Programs in Clean Technology, Yonsei University, Seoul 03722, Korea
| | - Jungho Hwang
- Graduate Programs in Clean Technology, Yonsei University, Seoul 03722, Korea
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Korea
| |
Collapse
|
12
|
Choi J, Hong SC, Kim W, Jung JH. Highly Enriched, Controllable, Continuous Aerosol Sampling Using Inertial Microfluidics and Its Application to Real-Time Detection of Airborne Bacteria. ACS Sens 2017; 2:513-521. [PMID: 28723191 DOI: 10.1021/acssensors.6b00753] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We report a novel microfluidic technique for sampling of aerosols into liquids. The two-phase fluid, sampling air and collecting liquid, forms a stratified flow in the curved microchannel. By passing fluids through the curved region, the particles are transferred from air into the liquid phase by the particle centrifugal and drag forces. This microfluidic-based aerosol-into-liquid sampling system, called the MicroSampler, is driven by particle inertial differences. To evaluate the physical particle collection efficiency of the MicroSampler, we used standard polystyrene-latex (PSL) particles ranging in size from 0.6 to 2.1 μm and measured particle concentrations upstream and downstream of the MicroSampler with an aerodynamic particle sizer. The cutoff diameter of particle collection was selected controlling the air flow velocity (microfluidic air flow of 0.6 L/min showed a particle collection efficiency of ∼98% at a particle diameter of 1 μm), and continuous enriched particle sampling was possible for real-time postprocessing application. With regard to biological collection efficiency, the MicroSampler showed superior microbial recovery (Staphylococcus epidermidis) compared to the conventional BioSampler technique. These results indicate that our MicroSampler can be used as a portable, cost-effective, simple, and continuous airborne microorganism collector for applications in real-time bioaerosol detection.
Collapse
Affiliation(s)
- Jeongan Choi
- Center
for Environment, Health, and Welfare Research, KIST School, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Department
of Mechanical Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Seung Chan Hong
- Center
for Environment, Health, and Welfare Research, KIST School, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Department
of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Woojin Kim
- Technology Convergence R&BD Group, Korea Institute of Industrial Technology, Daegu 42994, Republic of Korea
| | - Jae Hee Jung
- Center
for Environment, Health, and Welfare Research, KIST School, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Green School, Korea University, Seoul 02841, Republic of Korea
| |
Collapse
|
13
|
Zhou W, Orr MW, Lee VT, Zachariah MR. Synergistic effects of ultrafast heating and gaseous chlorine on the neutralization of bacterial spores. Chem Eng Sci 2016. [DOI: 10.1016/j.ces.2016.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
14
|
Choi J, Yang BJ, Bae GN, Jung JH. Herbal Extract Incorporated Nanofiber Fabricated by an Electrospinning Technique and its Application to Antimicrobial Air Filtration. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25313-20. [PMID: 26505783 DOI: 10.1021/acsami.5b07441] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recently, with the increased attention to indoor air quality, antimicrobial air filtration techniques have been studied widely to inactivate hazardous airborne microorganisms effectively. In this study, we demonstrate herbal extract incorporated (HEI) nanofibers synthesized by an electrospinning technique and their application to antimicrobial air filtration. As an antimicrobial herbal material, an ethanolic extract of Sophora flavescens, which exhibits great antibacterial activity against pathogens, was mixed with the polymer solution for the electrospinning process. We measured various characteristics of the synthesized HEI nanofibers, such as fiber morphology, fiber size distribution, and thermal stability. For application of the electrospun HEI nanofibers, we made highly effective air filters with 99.99% filtration efficiency and 99.98% antimicrobial activity against Staphylococcus epidermidis. The pressure drop across the HEI nanofiber air filter was 4.75 mmH2O at a face air velocity of 1.79 cm/s. These results will facilitate the implementation of electrospun HEI nanofiber techniques to control air quality and protect against hazardous airborne microorganisms.
Collapse
Affiliation(s)
- Jeongan Choi
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | - Byeong Joon Yang
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea
- Department of Electric Engineering, Seoul National University of Science and Technology , Gongneung-ro, Nowon-gu, Seoul 139-743, Republic of Korea
| | - Gwi-Nam Bae
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | - Jae Hee Jung
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea
| |
Collapse
|
15
|
Hwang GB, Sim KM, Bae GN, Jung JH. Synthesis of hybrid carbon nanotube structures coated with Sophora flavescens nanoparticles and their application to antimicrobial air filtration. JOURNAL OF AEROSOL SCIENCE 2015; 86:44-54. [PMID: 32226126 PMCID: PMC7094255 DOI: 10.1016/j.jaerosci.2015.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 03/28/2015] [Accepted: 04/12/2015] [Indexed: 05/23/2023]
Abstract
Controlling airborne microorganisms has become increasingly important with increase in human indoor activities, epidemic disease outbreaks, and airborne pathogen transmission. Treatments using antimicrobial nanoparticles have shown promise because of the high surface-to-volume ratio of nanoparticles compared to their bulk counterparts, and their unique physical and chemical properties. In this study, hybrid nanostructures of multi-walled carbon nanotubes (MWCNTs) coated with antimicrobial, natural product (NP) nanoparticles were synthesized using a twin-head electrospray system (THES). The coated nanoparticles were then used in antimicrobial air filters to increase their antimicrobial efficiency. Electrosprayed droplets were converted to NP nanoparticles and MWCNTs through ethanol evaporation. Oppositely charged NP nanoparticles and MWCNTs were coagulated via Coulombic collisions to form hybrid nanoparticles that were deposited continuously onto an air filter medium. The size distribution and composition of the hybrid NP/MWCNT particles were characterized using a wide-range particle spectrometer (WPS) and transmission electron microscope (TEM). The concentration of hybrid NP/MWCNT nanoparticles was lower than that of NP nanoparticles but higher than that of MWCNTs and showed a bimodal size distribution with peak diameters of 21.1 and 49 nm. TEM analyses confirmed that the NP nanoparticles were attached to the MWCNT surface with a density of ~4-9 particles/MWCNT. When deposited onto the filter medium, NP/MWCNT particles formed dendrites on the filter׳s fiber surface. The filtration efficiency and pressure drop of the NP/MWCNT-coated filters were higher than those of pristine, NP nanoparticles-coated or MWCNTs-coated filters. The hybrid filter also exhibited stronger antimicrobial activity than those of NP or MWCNT-coated filters at identical deposited volumes (1.1×10-2 cm3/cm2 filter). Ninety-five percent of the tested bacterial aerosols were inactivated on the NP/MWCNTs filter while only <70% were inactivated on NP- or MWCNT-coated filters.
Collapse
Affiliation(s)
- Gi Byoung Hwang
- Center for Environment, Health and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5 Seongbuk-gu, Seoul 136-791, Republic of Korea
- Materials Chemistry Research Center, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Kyoung Mi Sim
- Center for Environment, Health and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5 Seongbuk-gu, Seoul 136-791, Republic of Korea
| | - Gwi-Nam Bae
- Center for Environment, Health and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5 Seongbuk-gu, Seoul 136-791, Republic of Korea
| | - Jae Hee Jung
- Center for Environment, Health and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5 Seongbuk-gu, Seoul 136-791, Republic of Korea
| |
Collapse
|
16
|
Hwang GB, Heo KJ, Yun JH, Lee JE, Lee HJ, Nho CW, Bae GN, Jung JH. Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles. PLoS One 2015; 10:e0126481. [PMID: 25974109 PMCID: PMC4431859 DOI: 10.1371/journal.pone.0126481] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/03/2015] [Indexed: 11/19/2022] Open
Abstract
Controlling bioaerosols has become more important with increasing participation in indoor activities. Treatments using natural-product nanomaterials are a promising technique because of their relatively low toxicity compared to inorganic nanomaterials such as silver nanoparticles or carbon nanotubes. In this study, antimicrobial filters were fabricated from natural Euscaphis japonica nanoparticles, which were produced by nebulizing E. japonica extract. The coated filters were assessed in terms of pressure drop, antimicrobial activity, filtration efficiency, major chemical components, and cytotoxicity. Pressure drop and antimicrobial activity increased as a function of nanoparticle deposition time (590, 855, and 1150 µg/cm2(filter) at 3-, 6-, and 9-min depositions, respectively). In filter tests, the antimicrobial efficacy was greater against Staphylococcus epidermidis than Micrococcus luteus; ~61, ~73, and ~82% of M. luteus cells were inactivated on filters that had been coated for 3, 6, and 9 min, respectively, while the corresponding values were ~78, ~88, and ~94% with S. epidermidis. Although statistically significant differences in filtration performance were not observed between samples as a function of deposition time, the average filtration efficacy was slightly higher for S. epidermidis aerosols (~97%) than for M. luteus aerosols (~95%). High-performance liquid chromatography (HPLC) and electrospray ionization-tandem mass spectrometry (ESI/MS) analyses confirmed that the major chemical compounds in the E. japonica extract were 1(ß)-O-galloyl pedunculagin, quercetin-3-O-glucuronide, and kaempferol-3-O-glucoside. In vitro cytotoxicity and disk diffusion tests showed that E. japonica nanoparticles were less toxic and exhibited stronger antimicrobial activity toward some bacterial strains than a reference soluble nickel compound, which is classified as a human carcinogen. This study provides valuable information for the development of a bioaerosol control system that is environmental friendly and suitable for use in indoor environments.
Collapse
Affiliation(s)
- Gi Byoung Hwang
- Center For Environment, Health, and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul, Republic of Korea
- Materials Chemistry Research Centre, Department of Chemistry, University College London, 20 Gordon Street, London, United Kingdom
| | - Ki Joon Heo
- Center For Environment, Health, and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul, Republic of Korea
- Aerosol and Bioengineering Laboratory, College of Engineering, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul, Republic of Korea
| | - Ji Ho Yun
- Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do, Republic of Korea
| | - Jung Eun Lee
- Han-River Environment Research Center, National Institute of Environmental Research (NIER), Yangseo-myeon, Yangpyeong-gun, Gyeonggi-do, Republic of Korea
| | - Hee Ju Lee
- Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do, Republic of Korea
| | - Chu Won Nho
- Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do, Republic of Korea
| | - Gwi- Nam Bae
- Center For Environment, Health, and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul, Republic of Korea
| | - Jae Hee Jung
- Center For Environment, Health, and Welfare Research, Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul, Republic of Korea
| |
Collapse
|
17
|
Montesinos VN, Sleiman M, Cohn S, Litter MI, Destaillats H. Detection and quantification of reactive oxygen species (ROS) in indoor air. Talanta 2015; 138:20-27. [PMID: 25863366 DOI: 10.1016/j.talanta.2015.02.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/06/2015] [Accepted: 02/09/2015] [Indexed: 11/19/2022]
Abstract
Reactive oxygen species (ROS), such as free radicals and peroxides, are environmental trace pollutants potentially associated with asthma and airways inflammation. These compounds are often not detected in indoor air due to sampling and analytical limitations. This study developed and validated an experimental method to sample, identify and quantify ROS in indoor air using fluorescent probes. Tests were carried out simultaneously using three different probes: 2',7'-dichlorofluorescin (DCFH) to detect a broad range of ROS, Amplex ultra Red® (AuR) to detect peroxides, and terephthalic acid (TPA) to detect hydroxyl radicals (HO(•)). For each test, air samples were collected using two impingers in series kept in an ice bath, containing each 10 mL of 50 mM phosphate buffer at pH 7.2. In tests with TPA, that probe was also added to the buffer prior to sampling; in the other two tests, probes and additional reactants were added immediately after sampling. The concentration of fluorescent byproducts was determined fluorometrically. Calibration curves were developed by reacting DCFH and AuR with known amounts of H2O2, and using known amounts of 2-hydroxyterephthalic acid (HTPA) for TPA. Low detection limits (9-13 nM) and quantification limits (18-22 nM) were determined for all three probes, which presented a linear response in the range 10-500 nM for AuR and TPA, and 100-2000 nM for DCFH. High collection efficiency (CE) and recovery efficiency (RE) were observed for DCFH (CE=RE=100%) and AuR (CE=100%; RE=73%) by sampling from a laboratory-developed gas phase H2O2 generator. Interference of co-occurring ozone was evaluated and quantified for the three probes by sampling from the outlet of an ozone generator. The method was demonstrated by sampling air emitted by two portable air cleaners: a strong ozone generator (AC1) and a plasma generator (AC2). High ozone levels emitted by AC1 did not allow for simultaneous determination of ROS levels due to high background levels associated with ozone decomposition in the buffer. However, emitted ROS were quantified at the outlet of AC2 using two of the three probes. With AuR, the concentration of peroxides in air emitted by the air cleaner was 300 ppt of H2O2 equivalents. With TPA, the HO(•) concentration was 47 ppt. This method is best suited to quantify ROS in the presence of low ozone levels.
Collapse
Affiliation(s)
- V Nahuel Montesinos
- Comisión Nacional de Energía Atómica, Avenida Gral. Paz 1499, 1650 San Martín, Provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Rivadavia 1917, 1033 Ciudad Autónoma de Buenos Aires, Argentina; Universidad de Buenos Aires, FCEN, INQUIMAE, DQIAQF, Ciudad Universitaria Pabellón II, 1428 Ciudad Autónoma de Buenos Aires, Argentina
| | - Mohamad Sleiman
- Lawrence Berkeley National Laboratory, Indoor Environment Group, 1 Cyclotron Road MS 70-108B, Berkeley, CA, USA; Clermont Université, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, BP 80026, F-63177 Aubière, France
| | - Sebastian Cohn
- Lawrence Berkeley National Laboratory, Indoor Environment Group, 1 Cyclotron Road MS 70-108B, Berkeley, CA, USA
| | - Marta I Litter
- Comisión Nacional de Energía Atómica, Avenida Gral. Paz 1499, 1650 San Martín, Provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Rivadavia 1917, 1033 Ciudad Autónoma de Buenos Aires, Argentina; Universidad de General San Martín, Instituto de Investigación e Ingeniería Ambiental, Peatonal Belgrano 3563, 1650 San Martín, Pcia. Buenos Aires, Argentina
| | - Hugo Destaillats
- Lawrence Berkeley National Laboratory, Indoor Environment Group, 1 Cyclotron Road MS 70-108B, Berkeley, CA, USA.
| |
Collapse
|
18
|
Xing Y, Li A, Felker DL, Burggraf LW. Nanoscale structural and mechanical analysis of Bacillus anthracis spores inactivated with rapid dry heating. Appl Environ Microbiol 2014; 80:1739-49. [PMID: 24375142 PMCID: PMC3957622 DOI: 10.1128/aem.03483-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/21/2013] [Indexed: 11/20/2022] Open
Abstract
Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating.
Collapse
Affiliation(s)
- Yun Xing
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee, USA
| | - Alex Li
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
| | - Daniel L. Felker
- Department of Systems Engineering & Management, Air Force Institute of Technology, WPAFB, Dayton, Ohio, USA
| | - Larry W. Burggraf
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
| |
Collapse
|
19
|
Paladini F, Cooper IR, Pollini M. Development of antibacterial and antifungal silver-coated polyurethane foams as air filtration units for the prevention of respiratory diseases. J Appl Microbiol 2013; 116:710-7. [DOI: 10.1111/jam.12402] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 10/29/2013] [Accepted: 11/19/2013] [Indexed: 01/10/2023]
Affiliation(s)
- F. Paladini
- Department of Engineering for Innovation; University of Salento; Lecce Italy
| | - I. R. Cooper
- School of Pharmacy and Biomolecular Science; University of Brighton; Brighton UK
| | - M. Pollini
- Department of Engineering for Innovation; University of Salento; Lecce Italy
- Silvertech Ltd; Lecce Italy
| |
Collapse
|
20
|
Real-time monitoring of bioaerosols via cell-lysis by air ion and ATP bioluminescence detection. Biosens Bioelectron 2013; 52:379-83. [PMID: 24080217 DOI: 10.1016/j.bios.2013.09.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/30/2013] [Accepted: 09/09/2013] [Indexed: 11/23/2022]
Abstract
In this study, we introduce a methodology for disrupting cell membranes with air ions coupled with ATP bioluminescence detection for real-time monitoring of bioaerosol concentrations. A carbon fiber ionizer was used to extract ATP from bacterial cells for generating ATP bioluminescence. Our methodology was tested using Staphylococcus epidermidis and Escherichia coli, which were aerosolized with an atomizer, and then indoor bioaerosols were also used for testing the methodology. Bioaerosol concentrations were estimated without culturing which requires several days for colony formation. Correlation equations were obtained for results acquired using our methodology (Relative Luminescent Unit (RLU)/m(3)) and a culture-based (Colony Forming Unit (CFU)/m(3)) method; CFU/m(3)=1.8 × measured RLU/m(3) for S. epidermidis and E. coli, and CFU/m(3)=1.1 × measured RLU/m(3) for indoor bioaerosols under the experimental conditions. Our methodology is an affordable solution for rapidly monitoring bioaerosols due to rapid detection time (cell-lysis time: 3 min; bioluminescence detection time: <1 min) and easy operation.
Collapse
|
21
|
Ariya PA, Kos G, Mortazavi R, Hudson ED, Kanthasamy V, Eltouny N, Sun J, Wilde C. Bio-organic materials in the atmosphere and snow: measurement and characterization. Top Curr Chem (Cham) 2013; 339:145-99. [PMID: 23832685 DOI: 10.1007/128_2013_461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Bio-organic chemicals are ubiquitous in the Earth's atmosphere and at air-snow interfaces, as well as in aerosols and in clouds. It has been known for centuries that airborne biological matter plays various roles in the transmission of disease in humans and in ecosystems. The implication of chemical compounds of biological origins in cloud condensation and in ice nucleation processes has also been studied during the last few decades, and implications have been suggested in the reduction of visibility, in the influence on oxidative potential of the atmosphere and transformation of compounds in the atmosphere, in the formation of haze, change of snow-ice albedo, in agricultural processes, and bio-hazards and bio-terrorism. In this review we critically examine existing observation data on bio-organic compounds in the atmosphere and in snow. We also review both conventional and cutting-edge analytical techniques and methods for measurement and characterisation of bio-organic compounds and specifically for microbial communities, in the atmosphere and snow. We also explore the link between biological compounds and nucleation processes. Due to increased interest in decreasing emissions of carbon-containing compounds, we also briefly review (in an Appendix) methods and techniques that are currently deployed for bio-organic remediation.
Collapse
Affiliation(s)
- P A Ariya
- Departments of Chemistry, Atmospheric and Oceanic Sciences, McGill University, 801 Sherbrooke St. W., Montreal, QC, Canada,
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Chong ES, Hwang GB, Nho CW, Kwon BM, Lee JE, Seo S, Bae GN, Jung JH. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 444:110-114. [PMID: 23262327 DOI: 10.1016/j.scitotenv.2012.11.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/24/2012] [Accepted: 11/21/2012] [Indexed: 05/27/2023]
Abstract
Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ~90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens.
Collapse
Affiliation(s)
- Eui-Seok Chong
- Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Park CW, Hwang J. Susceptibility constants of airborne bacteria to dielectric barrier discharge for antibacterial performance evaluation. JOURNAL OF HAZARDOUS MATERIALS 2013; 244-245:421-8. [PMID: 23274942 PMCID: PMC7117052 DOI: 10.1016/j.jhazmat.2012.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 05/21/2023]
Abstract
Dielectric barrier discharge (DBD) is a promising method to remove contaminant bioaerosols. The collection efficiency of a DBD reactor is an important factor for determining a reactor's removal efficiency. Without considering collection, simply defining the inactivation efficiency based on colony counting numbers for DBD as on and off may lead to overestimation of the inactivation efficiency of the DBD reactor. One-pass removal tests of bioaerosols were carried out to deduce the inactivation efficiency of the DBD reactor using both aerosol- and colony-counting methods. Our DBD reactor showed good performance for removing test bioaerosols for an applied voltage of 7.5 kV and a residence time of 0.24s, with η(CFU), η(Number), and η(Inactivation) values of 94%, 64%, and 83%, respectively. Additionally, we introduce the susceptibility constant of bioaerosols to DBD as a quantitative parameter for the performance evaluation of a DBD reactor. The modified susceptibility constant, which is the ratio of the susceptibility constant to the volume of the plasma reactor, has been successfully demonstrated for the performance evaluation of different sized DBD reactors under different DBD operating conditions. Our methodology will be used for design optimization, performance evaluation, and prediction of power consumption of DBD for industrial applications.
Collapse
Affiliation(s)
- Chul Woo Park
- School of Mechanical Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | | |
Collapse
|
24
|
Hwang GB, Lee JE, Nho CW, Lee BU, Lee SJ, Jung JH, Bae GN. Short-term effect of humid airflow on antimicrobial air filters using Sophora flavescens nanoparticles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 421-422:273-279. [PMID: 22369866 DOI: 10.1016/j.scitotenv.2012.01.060] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 01/18/2012] [Accepted: 01/27/2012] [Indexed: 05/31/2023]
Abstract
Bioaerosols have received social and scientific attention because they can be hazardous to human health. Recently, antimicrobial treatments using natural products have been used to improve indoor air quality (IAQ) since they are typically less toxic to humans compared to other antimicrobial substances such as silver, carbon nanotubes, and metal oxides. Few studies, however, have examined how environmental conditions such as the relative humidity (RH), surrounding temperature, and retention time of bacteria on filters affect the filtration and antimicrobial characteristics of a filter treated with such natural products. In this study, we investigated changes in the morphology of the natural nanoparticles, pressure drop, filtration efficiency, and the inactivation rate caused by the short-term effect of humid airflow on antimicrobial fiber filters. Nanoparticles of Sophora flavescens were deposited on the filter media surface using an aerosol process. We observed coalescence and morphological changes of the nanoparticles on fiber filters under humid conditions of an RH >50%. The level of coalescence in these nanoparticles increased with increasing RH. Filters exposed to an RH of 25% have a higher pressure drop than those exposed to an RH >50%. In an inactivation test against Staphylococcus epidermidis bacterial aerosol, the inactivation efficiency at an RH of 25% was higher than that at an RH of 57% or 82%. To effectively apply antimicrobial filters using natural products in the environment, one must characterize the filters under various environmental conditions. Thus, this study provides important information on the use of antimicrobial filters made of natural products.
Collapse
Affiliation(s)
- Gi Byoung Hwang
- Environmental Sensor System Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | | | | | | | | | | | | |
Collapse
|
25
|
Jung JH, Lee JE, Bae GN. Real-time measurement of UV-inactivated Escherichia coli bacterial particles by electrospray-assisted UVAPS spectrometry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 409:3249-3255. [PMID: 21621246 DOI: 10.1016/j.scitotenv.2011.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 04/23/2011] [Accepted: 05/04/2011] [Indexed: 05/30/2023]
Abstract
The ultraviolet aerodynamic particle sizer (UVAPS) is a novel commercially available aerosol spectrometer for real-time continuous monitoring of viable bioaerosols, based on fluorescence from living microorganisms. In a previous study, we developed an electrospray-assisted UVAPS using biological electrospray techniques, which have the advantage of generating non-agglomerated single particles by the repulsive electrical forces. With this electrospraying of suspensions containing microorganisms, the analytical system can supply more accurate and quantitative information about living microorganisms than with conventional aerosolization. Using electrospray-assisted UVAPS, we investigated the characteristics of bacterial particles with various viabilities in real-time. Escherichia coli was used as the test microorganism, and its initial viability was controlled by the degree of exposure to UV irradiation. In the stable cone-jet domain, the particle size distributions of test bacterial particles remained almost uniform regardless of the degree of UV inactivation. However, the fluorescence spectra of the bacterial particles changed with the degree of UV inactivation. The fluorescence characteristics of UV-inactivated bacterial particles tended to show a similar decline with viability, determined by the sampling and culture method, although the percentage showing fluorescence was higher than that showing viability.
Collapse
Affiliation(s)
- Jae Hee Jung
- Environment Sensor System Research Center, Korea Institute of Science and Technology, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | | | | |
Collapse
|
26
|
Johansson E, Adhikari A, Reponen T, Yermakov M, Grinshpun SA. Association between increased DNA mutational frequency and thermal inactivation of aerosolized Bacillus spores exposed to dry heat. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2011; 45:376-381. [PMID: 31660000 PMCID: PMC6816487 DOI: 10.1080/02786826.2010.538452] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Inactivation of viable bioaerosol particles, especially stress-resistant microorganisms, has important implications for biodefense and air quality control. It has earlier been shown that the loss of viability of bacterial endospores due to exposure to dry heat is associated with mutational damage. Previous studies, however, used non-aerosolized spores, long exposure times, and moderately elevated temperatures. This study was designed to investigate the mechanism of inactivation of aerosolized Bacillus endospores exposed to high temperatures for sub-second time periods. Bioaerosol was tested in a continuous air flow chamber under two flow rates, 18 L/min and 36 L/min. The chamber had a cylindrical electric heating element installed along its axis. The estimated characteristic exposure temperature (T exposure ) ranged from 164°C to 277°C (with an uncertainty of 21-26°C). To quantify mutational frequency, spores were cultivated after dry heat exposure on tryptic-soy agar and on antibiotic nalidixic acid media. Increases in the exposure temperature caused viability loss and increase in mutational frequency of the spore DNA. Significant association was found between the inactivation factor and the mutational frequency ratio (heat exposed versus non-exposed) with R2 of 0.985 for both flow rates combined. The results suggest that mutational damage is involved in the causal chain of events leading to inactivation of aerosolized endospores exposed to heat for sub-second time periods.
Collapse
|
27
|
Hwang GB, Jung JH, Jeong TG, Lee BU. Effect of hybrid UV-thermal energy stimuli on inactivation of S. epidermidis and B. subtilis bacterial bioaerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:5903-5909. [PMID: 20822796 DOI: 10.1016/j.scitotenv.2010.08.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 08/06/2010] [Accepted: 08/07/2010] [Indexed: 05/29/2023]
Abstract
Bioaerosols have become an increasingly important issue due to their harmful effects on human health. As the concern over airborne microorganisms grows, so does the need to develop and study efficient methods of controlling them. In this study, we designed a hybrid system involving ultraviolet (UV) irradiation and thermal energy and investigated its effects on bacterial bioaerosols, followed by a comparison with thermal energy alone and UV irradiation alone. The results show that the hybrid effect caused no variation in the shape of the normalized particle size distributions of S. epidermidis and B. subtilis bioaerosols. However, a physical transport loss of bacterial bioaerosols developed as the temperature inside the glass quartz tube increased. When bacterial bioaerosols were simultaneously exposed to UV irradiation and thermal energy for less than 1.05 s, more than 99% of S. epidermidis bioaerosols were inactivated at 120 °C with exposure to one UV lamp and at 80 °C with exposure to two UV lamps; and 93.5% and 98.5% of B. subtilis bioaerosols were inactivated at 280 °C with exposure to one and two UV lamps, respectively. Moreover, the hybrid UV-thermal stimuli significantly reduced the concentration of ozone, which is a secondary UV-induced pollutant. Our results show that to obtain the same inactivation efficiency, the hybrid UV-thermal stimuli were more efficient than thermal energy alone in terms of energy consumption and produced significantly less ozone than UV irradiation alone. The hybrid stimuli also had higher inactivation efficiency than UV alone. Therefore, these results provide valuable information for the development of new methods for controlling bioaerosols.
Collapse
Affiliation(s)
- Gi Byoung Hwang
- Aerosol and Bioengineering Laboratory, Department of Mechanical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-Gu, Seoul, 143-701, Republic of Korea
| | | | | | | |
Collapse
|