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So D, Yao CK, Gill PA, Thwaites PA, Ardalan ZS, McSweeney CS, Denman SE, Chrimes AF, Muir JG, Berean KJ, Kalantar‐Zadeh K, Gibson PR. Detection of changes in regional colonic fermentation in response to supplementing a low FODMAP diet with dietary fibres by hydrogen concentrations, but not by luminal pH. Aliment Pharmacol Ther 2023; 58:417-428. [PMID: 37386938 PMCID: PMC10946934 DOI: 10.1111/apt.17629] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/04/2023] [Accepted: 06/15/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND Carbohydrate fermentation plays a pivotal role in maintaining colonic health with excessive proximal and deficient distal fermentation being detrimental. AIMS To utilise telemetric gas- and pH-sensing capsule technologies for defining patterns of regional fermentation following dietary manipulations, alongside conventional techniques of measuring fermentation. METHODS In a double-blind crossover trial, 20 patients with irritable bowel syndrome were fed low FODMAP diets that included no extra fibre (total fibre content 24 g/day), or additional poorly fermented fibre, alone (33 g/day) or with fermentable fibre (45 g/day) for 2 weeks. Plasma and faecal biochemistry, luminal profiles defined by tandem gas- and pH-sensing capsules, and faecal microbiota were assessed. RESULTS Plasma short-chain fatty acid (SCFA) concentrations (μmol/L) were median (IQR) 121 (100-222) with fibre combination compared with 66 (44-120) with poorly fermented fibre alone (p = 0.028) and 74 (55-125) control (p = 0.069), but no differences in faecal content were observed. Luminal hydrogen concentrations (%), but not pH, were higher in distal colon (mean 4.9 [95% CI: 2.2-7.5]) with fibre combination compared with 1.8 (0.8-2.8) with poorly fermented fibre alone (p = 0.003) and 1.9 (0.7-3.1) control (p = 0.003). Relative abundances of saccharolytic fermentative bacteria were generally higher in association with supplementation with the fibre combination. CONCLUSIONS A modest increase in fermentable plus poorly fermented fibres had minor effects on faecal measures of fermentation, despite increases in plasma SCFA and abundance of fermentative bacteria, but the gas-sensing capsule, not pH-sensing capsule, detected the anticipated propagation of fermentation distally in the colon. The gas-sensing capsule technology provides unique insights into localisation of colonic fermentation. TRIAL REGISTRATION ACTRN12619000691145.
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Affiliation(s)
- Daniel So
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Chu K. Yao
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Paul A. Gill
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Phoebe A. Thwaites
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Zaid S. Ardalan
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Chris S. McSweeney
- Agriculture and FoodCommonwealth Scientific and Industrial Research OrganisationSt. LuciaAustralia
| | - Stuart E. Denman
- Agriculture and FoodCommonwealth Scientific and Industrial Research OrganisationSt. LuciaAustralia
| | - Adam F. Chrimes
- Atmo BiosciencesMelbourneAustralia
- School of Engineering, RMIT UniversityMelbourneAustralia
| | - Jane G. Muir
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
| | - Kyle J. Berean
- Atmo BiosciencesMelbourneAustralia
- School of Engineering, RMIT UniversityMelbourneAustralia
| | - Kourosh Kalantar‐Zadeh
- School of Chemical Engineering, University of New South WalesSydneyAustralia
- Faculty of EngineeringSchool of Chemical and Biomolecular Engineering, The University of SydneySydneyAustralia
| | - Peter R. Gibson
- Department of GastroenterologyCentral Clinical School, Monash University and Alfred HealthMelbourneAustralia
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2
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Thwaites PA, Yao CK, Maggo J, John J, Chrimes AF, Burgell RE, Muir JG, Parker FC, So D, Kalantar‐Zadeh K, Gearry RB, Berean KJ, Gibson PR. Comparison of gastrointestinal landmarks using the gas-sensing capsule and wireless motility capsule. Aliment Pharmacol Ther 2022; 56:1337-1348. [PMID: 36082475 PMCID: PMC9826325 DOI: 10.1111/apt.17216] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 07/29/2022] [Accepted: 08/25/2022] [Indexed: 01/30/2023]
Abstract
BACKGROUND Accurate definition of the gastroduodenal and ileocaecal junctions (GDJ, ICJ) is essential for the measurement of regional transit times. AIMS To compare the assessment of these landmarks using the novel gas-sensing capsule and validated wireless motility capsule (WMC), and to evaluate intra-subject variance in transit times METHODS: Healthy subjects ingested the gas-sensing capsule and WMC tandemly in random order. Inter-observer agreement was evaluated by intra-class correlation coefficient (ICC). Agreement between the paired devices' transit times was assessed using Bland-Altman analysis; coefficient of variation was performed to express intra-individual variance in transit times. Similar analyses were completed with tandemly ingested gas-sensing capsules. RESULTS The inter-observer agreement for landmarks for both capsules was excellent (mean ICC ≥0.97) in 50 studies. The GDJ was identifiable in 92% of the gas-sensing capsule studies versus 82% of the WMC studies (p = 0.27); the ICJ in 96% versus 84%, respectively (p = 0.11). In the primary cohort (n = 26), median regional transit times differed by less than 6 min between paired capsules. Bland-Altman revealed a bias of -0.12 (95% limits of agreement, -0.94 to 0.70) hours for GDJ and - 0.446 (-2.86 to 2.0) hours for ICJ. Similar results were found in a demographically distinct validation cohort (n = 24). For tandemly ingested gas-sensing capsules, coefficients of variation of transit times were 11%-35%, which were similar to variance between the paired gas-sensing capsule and WMC, as were the biases. The capsules were well tolerated. CONCLUSIONS Key anatomical landmarks are accurately identified with the gas-sensing capsule in healthy individuals. Intra-individual differences in transit times between capsules are probably due to physiological factors. Studies in populations with gastrointestinal diseases are now required.
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Affiliation(s)
- Phoebe A. Thwaites
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Chu K. Yao
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | | | - James John
- Atmo BiosciencesMelbourneVictoriaAustralia
| | - Adam F. Chrimes
- Atmo BiosciencesMelbourneVictoriaAustralia,School of EngineeringRMIT UniversityMelbourneVictoriaAustralia
| | - Rebecca E. Burgell
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Jane G. Muir
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Francis C. Parker
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Daniel So
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Kourosh Kalantar‐Zadeh
- School of Chemical EngineeringUniversity of New South WalesSydneyNew South WalesAustralia
| | | | - Kyle J. Berean
- Atmo BiosciencesMelbourneVictoriaAustralia,School of EngineeringRMIT UniversityMelbourneVictoriaAustralia
| | - Peter R. Gibson
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia,School of EngineeringRMIT UniversityMelbourneVictoriaAustralia
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3
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Broadley LH, Chrimes AF, Mitchell A. Fringe analysis approach for imaging surface undulations on technical surfaces. Opt Express 2021; 29:33067-33076. [PMID: 34809125 DOI: 10.1364/oe.439052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Automated defect inspection is becoming increasingly important for advanced manufacturing. The ability to automatically inspect for critical defects early in the production cycle can reduce production costs and resources on unnecessary manufacturing steps. While there are many inspection techniques available, samples from early in a production workflow can prove challenging as they may still have systematic tooling marks, causing preferential scattering and hindering defect extraction. We propose a new imaging technique that exploits the preferential scattering from a technical surface to generate predictable fringe patterns on the sample's surface using only an array of LEDs. The patterns from this adapted fringe projection technique are imaged, and phase shifting algorithms are used to recover surface undulations on the sample. We implement this technique in the context of Hard Disk Drive platters that exhibit tooling marks from the lapping process and show that it is possible to image both highly scattering pits and scratches, as well as slow surface undulations with the same apparatus.
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Berean KJ, Ha N, Ou JZ, Chrimes AF, Grando D, Yao CK, Muir JG, Ward SA, Burgell RE, Gibson PR, Kalantar-Zadeh K. The safety and sensitivity of a telemetric capsule to monitor gastrointestinal hydrogen production in vivo in healthy subjects: a pilot trial comparison to concurrent breath analysis. Aliment Pharmacol Ther 2018; 48:646-654. [PMID: 30067289 DOI: 10.1111/apt.14923] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/07/2018] [Accepted: 07/06/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Intestinal gases are currently used for the diagnosis of disorders including small intestinal bacterial overgrowth and carbohydrate malabsorption. AIM To compare the performance of measuring hydrogen production within the gut directly with the telemetric gas-sensing capsule with that of indirect measurement through breath testing. METHODS Using standard breath testing protocols, the capsules and breath tests were simultaneously evaluated in a single-blinded trial in 12 healthy subjects. Eight received a single dose of 1.25-40 g inulin and four 20 or 40 g glucose. Safety and reliability of the capsules were also assessed. RESULTS There were no reported adverse events. All capsules were retrieved and operated without failure. Capsule measurements were in agreement with breath test measurements in magnitude but not in timing; minimal hydrogen production was observed after glucose ingestion and capsule measurements correlated with breath hydrogen after ingestion of 40 g inulin. A dose-dependent increase in concentration of hydrogen was observed from the capsule following ingestion of inulin as low as 1.25 g compared with >10 g for breath measurements. Specifically, the capsule measured >3000 times higher concentrations of hydrogen compared to breath tests, resulting in a signal-to-noise ratio of 23.4 for the capsule compared to 4.2 for the breath test. CONCLUSIONS The capsule showed high sensitivity and signal-to-noise ratio in measuring luminal hydrogen concentrations, provided information on the site of intestinal gas production, and demonstrated safety and reliability. The capsule has potential for improving diagnostic precision for disorders such as small intestinal bacterial overgrowth.
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Affiliation(s)
- Kyle J Berean
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Nam Ha
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Jian Zhen Ou
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Adam F Chrimes
- School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Danilla Grando
- School of Science, RMIT University, Bundoora, Victoria, Australia
| | - Chu K Yao
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Jane G Muir
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Stephanie A Ward
- Monash School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Rebecca E Burgell
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Peter R Gibson
- Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia
| | - Kourosh Kalantar-Zadeh
- School of Engineering, RMIT University, Melbourne, Victoria, Australia.,School of Chemical Engineering, University of New South Wales (UNSW), Kensington, Victoria, Australia
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5
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Khan H, Zavabeti A, Wang Y, Harrison CJ, Carey BJ, Mohiuddin M, Chrimes AF, De Castro IA, Zhang BY, Sabri YM, Bhargava SK, Ou JZ, Daeneke T, Russo SP, Li Y, Kalantar-Zadeh K. Quasi physisorptive two dimensional tungsten oxide nanosheets with extraordinary sensitivity and selectivity to NO 2. Nanoscale 2017; 9:19162-19175. [PMID: 29186236 DOI: 10.1039/c7nr05403c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Attributing to their distinct thickness and surface dependent physicochemical properties, two dimensional (2D) nanostructures have become an area of increasing interest for interfacial interactions. Effectively, properties such as high surface-to-volume ratio, modulated surface activities and increased control of oxygen vacancies make these types of materials particularly suitable for gas-sensing applications. This work reports a facile wet-chemical synthesis of 2D tungsten oxide nanosheets by sonication of tungsten particles in an acidic environment and thermal annealing thereafter. The resultant product of large nanosheets with intrinsic substoichiometric properties is shown to be highly sensitive and selective to nitrogen dioxide (NO2) gas, which is a major pollutant. The strong synergy between polar NO2 molecules and tungsten oxide surface and also abundance of active surface sites on the nanosheets for molecule interactions contribute to the exceptionally sensitive and selective response. An extraordinary response factor of ∼30 is demonstrated to ultralow 40 parts per billion (ppb) NO2 at a relatively low operating temperature of 150 °C, within the physisorption temperature band for tungsten oxide. Selectivity to NO2 is demonstrated and the theory behind it is discussed. The structural, morphological and compositional characteristics of the synthesised and annealed materials are extensively characterised and electronic band structures are proposed. The demonstrated 2D tungsten oxide based sensing device holds the greatest promise for producing future commercial low-cost, sensitive and selective NO2 gas sensors.
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Affiliation(s)
- Hareem Khan
- School of Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria 3000, Australia.
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6
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A de Castro I, Chrimes AF, Zavabeti A, Berean KJ, Carey BJ, Zhuang J, Du Y, Dou SX, Suzuki K, Shanks RA, Nixon-Luke R, Bryant G, Khoshmanesh K, Kalantar-Zadeh K, Daeneke T. A Gallium-Based Magnetocaloric Liquid Metal Ferrofluid. Nano Lett 2017; 17:7831-7838. [PMID: 29095626 DOI: 10.1021/acs.nanolett.7b04050] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We demonstrate a magnetocaloric ferrofluid based on a gadolinium saturated liquid metal matrix, using a gallium-based liquid metal alloy as the solvent and suspension medium. The material is liquid at room temperature, while exhibiting spontaneous magnetization and a large magnetocaloric effect. The magnetic properties were attributed to the formation of gadolinium nanoparticles suspended within the liquid gallium alloy, which acts as a reaction solvent during the nanoparticle synthesis. High nanoparticle weight fractions exceeding 2% could be suspended within the liquid metal matrix. The liquid metal ferrofluid shows promise for magnetocaloric cooling due to its high thermal conductivity and its liquid nature. Magnetic and thermoanalytic characterizations reveal that the developed material remains liquid within the temperature window required for domestic refrigeration purposes, which enables future fluidic magnetocaloric devices. Additionally, the observed formation of nanometer-sized metallic particles within the supersaturated liquid metal solution has general implications for chemical synthesis and provides a new synthetic pathway toward metallic nanoparticles based on highly reactive rare earth metals.
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Affiliation(s)
- Isabela A de Castro
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
| | - Adam F Chrimes
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
| | - Ali Zavabeti
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
| | - Kyle J Berean
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
| | - Benjamin J Carey
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
| | - Jincheng Zhuang
- Institute for Superconducting and Electronic Materials, University of Wollongong , Wollongong, New South Wales 2500, Australia
| | - Yi Du
- Institute for Superconducting and Electronic Materials, University of Wollongong , Wollongong, New South Wales 2500, Australia
| | - Shi X Dou
- Institute for Superconducting and Electronic Materials, University of Wollongong , Wollongong, New South Wales 2500, Australia
| | - Kiyonori Suzuki
- Department of Materials Science and Engineering, Monash University , Clayton, Victoria 3168, Australia
| | - Robert A Shanks
- School of Science, RMIT University , Melbourne, Victoria 3001, Australia
| | - Reece Nixon-Luke
- Centre for Molecular and Nanoscale Physics, School of Science, RMIT University , Melbourne, Victoria 3001, Australia
| | - Gary Bryant
- Centre for Molecular and Nanoscale Physics, School of Science, RMIT University , Melbourne, Victoria 3001, Australia
| | | | | | - Torben Daeneke
- School of Engineering, RMIT University , Melbourne, Victoria 3001, Australia
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7
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Chrimes AF, Berean KJ, Mitchell A, Rosengarten G, Kalantar-zadeh K. Controlled Electrochemical Deformation of Liquid-Phase Gallium. ACS Appl Mater Interfaces 2016; 8:3833-3839. [PMID: 26820807 DOI: 10.1021/acsami.5b10625] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Pure gallium is a soft metal with a low temperature melting point of 29.8 °C. This low melting temperature can potentially be employed for creating optical components with changeable configurations on demand by manipulating gallium in its liquid state. Gallium is a smooth and highly reflective metal that can be readily maneuvered using electric fields. These features allow gallium to be used as a reconfigurable optical reflector. This work demonstrates the use of gallium for creating reconfigurable optical reflectors manipulated through the use of electric fields when gallium is in a liquid state. The use of gallium allows the formed structures to be frozen and preserved as long as the temperature of the metal remains below its melting temperature. The lens can be readily reshaped by raising the temperature above the melting point and reapplying an electric field to produce a different curvature of the gallium reflector.
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Affiliation(s)
- Adam F Chrimes
- Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich , Zürich 8093, Switzerland
- School of Engineering, RMIT University , Melbourne, Victoria 3000, Australia
| | - Kyle J Berean
- School of Engineering, RMIT University , Melbourne, Victoria 3000, Australia
| | - Arnan Mitchell
- School of Engineering, RMIT University , Melbourne, Victoria 3000, Australia
| | - Gary Rosengarten
- School of Engineering, RMIT University , Melbourne, Victoria 3000, Australia
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8
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Rezk AR, Carey B, Chrimes AF, Lau DWM, Gibson BC, Zheng C, Fuhrer MS, Yeo LY, Kalantar-Zadeh K. Acoustically-Driven Trion and Exciton Modulation in Piezoelectric Two-Dimensional MoS2. Nano Lett 2016; 16:849-55. [PMID: 26729449 DOI: 10.1021/acs.nanolett.5b02826] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
By exploiting the very recent discovery of the piezoelectricity in odd-numbered layers of two-dimensional molybdenum disulfide (MoS2), we show the possibility of reversibly tuning the photoluminescence of single and odd-numbered multilayered MoS2 using high frequency sound wave coupling. We observe a strong quenching in the photoluminescence associated with the dissociation and spatial separation of electrons-holes quasi-particles at low applied acoustic powers. At the same applied powers, we note a relative preference for ionization of trions into excitons. This work also constitutes the first visual presentation of the surface displacement in one-layered MoS2 using laser Doppler vibrometry. Such observations are associated with the acoustically generated electric field arising from the piezoelectric nature of MoS2 for odd-numbered layers. At larger applied powers, the thermal effect dominates the behavior of the two-dimensional flakes. Altogether, the work reveals several key fundamentals governing acousto-optic properties of odd-layered MoS2 that can be implemented in future optical and electronic systems.
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Affiliation(s)
| | | | | | | | | | - Changxi Zheng
- Monash Centre for Atomically Thin Materials, Monash University , Victoria 3800, Australia
| | - Michael S Fuhrer
- Monash Centre for Atomically Thin Materials, Monash University , Victoria 3800, Australia
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9
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Alsaif MMYA, Field MR, Daeneke T, Chrimes AF, Zhang W, Carey BJ, Berean KJ, Walia S, van Embden J, Zhang B, Latham K, Kalantar-Zadeh K, Ou JZ. Exfoliation Solvent Dependent Plasmon Resonances in Two-Dimensional Sub-Stoichiometric Molybdenum Oxide Nanoflakes. ACS Appl Mater Interfaces 2016; 8:3482-93. [PMID: 26795577 DOI: 10.1021/acsami.5b12076] [Citation(s) in RCA: 29] [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] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Few-layer two-dimensional (2D) molybdenum oxide nanoflakes are exfoliated using a grinding assisted liquid phase sonication exfoliation method. The sonication process is carried out in five different mixtures of water with both aprotic and protic solvents. We found that surface energy and solubility of mixtures play important roles in changing the thickness, lateral dimension, and synthetic yield of the nanoflakes. We demonstrate an increase in proton intercalation in 2D nanoflakes upon simulated solar light exposure. This results in substoichiometric flakes and a subsequent enhancement in free electron concentrations, producing plasmon resonances. Two plasmon resonance peaks associated with the thickness and the lateral dimension axes are observable in the samples, in which the plasmonic peak positions could be tuned by the choice of the solvent in exfoliating 2D molybdenum oxide. The extinction coefficients of the plasmonic absorption bands of 2D molybdenum oxide nanoflakes in all samples are found to be high (ε > 10(9) L mol(-1) cm(-1)). It is expected that the tunable plasmon resonances of 2D molybdenum oxide nanoflakes presented in this work can be used in future electronic, optical, and sensing devices.
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Affiliation(s)
- Manal M Y A Alsaif
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Matthew R Field
- RMIT Microscopy and Microanalysis Facility, RMIT University , Melbourne 3001, Australia
| | - Torben Daeneke
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Adam F Chrimes
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
- Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich , Zürich 8092, Switzerland
| | - Wei Zhang
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Benjamin J Carey
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Kyle J Berean
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Sumeet Walia
- Functional Materials and Microsystems Research Group, RMIT University , Melbourne 3001, Australia
| | - Joel van Embden
- School of Applied Sciences, RMIT University , Melbourne 3001, Australia
- CSIRO Manufacturing Flagship , Bayview Avenue, Clayton 3168, Australia
| | - Baoyue Zhang
- Xi'an Institute of Electromechanical Information Technology , Xi'an 710000, China
| | - Kay Latham
- School of Applied Sciences, RMIT University , Melbourne 3001, Australia
| | - Kourosh Kalantar-Zadeh
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
| | - Jian Zhen Ou
- School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia
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10
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Nguyen EP, Carey BJ, Ou JZ, van Embden J, Gaspera ED, Chrimes AF, Spencer MJS, Zhuiykov S, Kalantar-Zadeh K, Daeneke T. Electronic Tuning of 2D MoS2 through Surface Functionalization. Adv Mater 2015; 27:6225-9. [PMID: 26375859 DOI: 10.1002/adma.201503163] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/11/2015] [Indexed: 05/07/2023]
Abstract
The electronic properties of thiol-functionalized 2D MoS2 nanosheets are investigated. Shifts in the valence and conduction bands and Fermi levels are observed while bandgaps remain unaffected. These findings allow the tuning of energy barriers between 2D MoS2 and other materials, which can lead to improved control over 2D MoS2 -based electronic and optical devices and catalysts.
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Affiliation(s)
- Emily P Nguyen
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Benjamin J Carey
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Jian Zhen Ou
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Joel van Embden
- School of Applied Chemistry, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
- CSIRO Manufacturing Flagship, Bayview Ave, Clayton, Victoria, 3168, Australia
| | | | - Adam F Chrimes
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Michelle J S Spencer
- School of Applied Chemistry, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Serge Zhuiykov
- Division of Materials Science and Engineering, CSIRO, 37 Graham Road, Highett, Victoria, 3190, Australia
| | - Kourosh Kalantar-Zadeh
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
| | - Torben Daeneke
- School of Electrical and Computer Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria, 3000, Australia
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11
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Ou JZ, Ge W, Carey B, Daeneke T, Rotbart A, Shan W, Wang Y, Fu Z, Chrimes AF, Wlodarski W, Russo SP, Li YX, Kalantar-Zadeh K. Physisorption-Based Charge Transfer in Two-Dimensional SnS2 for Selective and Reversible NO2 Gas Sensing. ACS Nano 2015; 9:10313-23. [PMID: 26447741 DOI: 10.1021/acsnano.5b04343] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nitrogen dioxide (NO2) is a gas species that plays an important role in certain industrial, farming, and healthcare sectors. However, there are still significant challenges for NO2 sensing at low detection limits, especially in the presence of other interfering gases. The NO2 selectivity of current gas-sensing technologies is significantly traded-off with their sensitivity and reversibility as well as fabrication and operating costs. In this work, we present an important progress for selective and reversible NO2 sensing by demonstrating an economical sensing platform based on the charge transfer between physisorbed NO2 gas molecules and two-dimensional (2D) tin disulfide (SnS2) flakes at low operating temperatures. The device shows high sensitivity and superior selectivity to NO2 at operating temperatures of less than 160 °C, which are well below those of chemisorptive and ion conductive NO2 sensors with much poorer selectivity. At the same time, excellent reversibility of the sensor is demonstrated, which has rarely been observed in other 2D material counterparts. Such impressive features originate from the planar morphology of 2D SnS2 as well as unique physical affinity and favorable electronic band positions of this material that facilitate the NO2 physisorption and charge transfer at parts per billion levels. The 2D SnS2-based sensor provides a real solution for low-cost and selective NO2 gas sensing.
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Affiliation(s)
- Jian Zhen Ou
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Wanyin Ge
- The Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 200050 Shanghai, P.R. China
| | - Benjamin Carey
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Torben Daeneke
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Asaf Rotbart
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Wei Shan
- The Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 200050 Shanghai, P.R. China
| | - Yichao Wang
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Zhengqian Fu
- School of Physical Science and Technology, ShanghaiTech University , 200031 Shanghai, P.R. China
| | - Adam F Chrimes
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Wojtek Wlodarski
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
| | - Salvy P Russo
- School of Applied Sciences, RMIT University , Melbourne, VIC 3000 Australia
| | - Yong Xiang Li
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
- The Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 200050 Shanghai, P.R. China
- School of Physical Science and Technology, ShanghaiTech University , 200031 Shanghai, P.R. China
| | - Kourosh Kalantar-Zadeh
- School of Electrical and Computer Engineering, RMIT University , Melbourne, VIC 3000, Australia
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12
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Chrimes AF, Khodasevych I, Mitchell A, Rosengarten G, Kalantar-zadeh K. Dielectrophoretically controlled Fresnel zone plate. Lab Chip 2015; 15:1092-1100. [PMID: 25524620 DOI: 10.1039/c4lc01213e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Switchability is a highly sought after feature for planar optical systems. Suspensions of nanomaterials can be used for generating controllable changes in such systems. We report a planar diffractive microfluidic lens which integrates controlled dielectrophoresis (DEP) for trapping suspended nanomaterials. Silicon and tungsten oxide nanoparticle suspensions are used. These nanomaterials are trapped in such a way as to form alternating opaque and transparent rings using the DEP forces on demand. These rings form a planar diffractive Fresnel zone plate to focus the incident light. The Fresnel zone plate is tuned for the visible light region and the lens can be turned on (DEP applied) or off (DEP removed) in a controlled manner. This proof of concept demonstration can be further expanded for a variety of switchable optical devices and can be integrated with lab-on-a-chip and optofluidic devices.
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Affiliation(s)
- A F Chrimes
- School of Electrical and Computer Engineering, RMIT University, Melbourne, Australia.
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13
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Wang Y, Ou JZ, Chrimes AF, Carey BJ, Daeneke T, Alsaif MMYA, Mortazavi M, Zhuiykov S, Medhekar N, Bhaskaran M, Friend JR, Strano MS, Kalantar-Zadeh K. Plasmon resonances of highly doped two-dimensional MoS₂. Nano Lett 2015; 15:883-890. [PMID: 25562610 DOI: 10.1021/nl503563g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The exhibition of plasmon resonances in two-dimensional (2D) semiconductor compounds is desirable for many applications. Here, by electrochemically intercalating lithium into 2D molybdenum disulfide (MoS2) nanoflakes, plasmon resonances in the visible and near UV wavelength ranges are achieved. These plasmon resonances are controlled by the high doping level of the nanoflakes after the intercalation, producing two distinct resonance peak areas based on the crystal arrangements. The system is also benchmarked for biosensing using bovine serum albumin. This work provides a foundation for developing future 2D MoS2 based biological and optical units.
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Affiliation(s)
- Yichao Wang
- School of Electrical and Computer Engineering, RMIT University , Melbourne, Victoria 3000, Australia
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14
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Zhang W, Naidu BS, Ou JZ, O'Mullane AP, Chrimes AF, Carey BJ, Wang Y, Tang SY, Sivan V, Mitchell A, Bhargava SK, Kalantar-Zadeh K. Liquid metal/metal oxide frameworks with incorporated Ga2O3 for photocatalysis. ACS Appl Mater Interfaces 2015; 7:1943-8. [PMID: 25543876 DOI: 10.1021/am5077364] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Solvothermally synthesized Ga2O3 nanoparticles are incorporated into liquid metal/metal oxide (LM/MO) frameworks in order to form enhanced photocatalytic systems. The LM/MO frameworks, both with and without incorporated Ga2O3 nanoparticles, show photocatalytic activity due to a plasmonic effect where performance is related to the loading of Ga2O3 nanoparticles. Optimum photocatalytic efficiency is obtained with 1 wt % incorporation of Ga2O3 nanoparticles. This can be attributed to the sub-bandgap states of LM/MO frameworks, contributing to pseudo-ohmic contacts which reduce the free carrier injection barrier to Ga2O3.
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Affiliation(s)
- Wei Zhang
- School of Electrical and Computer Engineering, RMIT University , Melbourne VIC 3001, Australia
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15
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Alsaif MMYA, Field MR, Murdoch BJ, Daeneke T, Latham K, Chrimes AF, Zoolfakar AS, Russo SP, Ou JZ, Kalantar-zadeh K. Substoichiometric two-dimensional molybdenum oxide flakes: a plasmonic gas sensing platform. Nanoscale 2014; 6:12780-91. [PMID: 25225830 DOI: 10.1039/c4nr03073g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Two-dimensional (2D) molybdenum oxides at their various stoichiometries are promising candidates for generating plasmon resonances in visible light range. Herein, we demonstrate plasmonic 2D molybdenum oxide flakes for gas sensing applications, in which hydrogen (H2) is selected as a model gas. The 2D molybdenum oxide flakes are obtained using a grinding-assisted liquid exfoliation method and exposed to simulated sunlight to acquire its substoichiometric quasi-metallic form. After the exposure to H2 gas molecules, the quasi-metallic molybdenum oxide flakes are partially transformed into semiconducting states, thus gradually losing their plasmonic properties. The novel 2D plasmonic sensing platform is tested using different concentrations of H2 gas at various operating temperatures to comprehensively assess its sensing performance. The presented 2D plasmonic system offers great opportunities for future sensing and optical applications.
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Affiliation(s)
- Manal M Y A Alsaif
- School of Electrical and Computer Engineering, RMIT University, Melbourne, Victoria, Australia.
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16
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Ou JZ, Chrimes AF, Wang Y, Tang SY, Strano MS, Kalantar-zadeh K. Ion-driven photoluminescence modulation of quasi-two-dimensional MoS2 nanoflakes for applications in biological systems. Nano Lett 2014; 14:857-63. [PMID: 24397241 DOI: 10.1021/nl4042356] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Quasi-two-dimensional (quasi-2D) molybdenum disulfide (MoS2) is a photoluminescence (PL) material with unique properties. The recent demonstration of its PL, controlled by the intercalation of positive ions, can lead to many opportunities for employing this quasi-2D material in ion-related biological applications. Here, we present two representative models of biological systems that incorporate the ion-controlled PL of quasi-2D MoS2 nanoflakes. The ion exchange behaviors of these two models are investigated to reveal enzymatic activities and cell viabilities. While the ion intercalation of MoS2 in enzymatic activities is enabled via an external applied voltage, the intercalation of ions in cell viability investigations occurs in the presence of the intrinsic cell membrane potential.
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Affiliation(s)
- Jian Zhen Ou
- School of Electrical and Computer Engineering, RMIT University , Melbourne, Victoria 3001, Australia
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17
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Chrimes AF, Khoshmanesh K, Stoddart PR, Mitchell A, Kalantar-Zadeh K. Microfluidics and Raman microscopy: current applications and future challenges. Chem Soc Rev 2014; 42:5880-906. [PMID: 23624774 DOI: 10.1039/c3cs35515b] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Raman microscopy systems are becoming increasingly widespread and accessible for characterising chemical species. Microfluidic systems are also progressively finding their way into real world applications. Therefore, it is anticipated that the integration of Raman systems with microfluidics will become increasingly attractive and practical. This review aims to provide an overview of Raman microscopy-microfluidics integrated systems for researchers who are actively interested in utilising these tools. The fundamental principles and application strengths of Raman microscopy are discussed in the context of microfluidics. Various configurations of microfluidics that incorporate Raman microscopy methods are presented, with applications highlighted. Data analysis methods are discussed, with a focus on assisting the interpretation of Raman-microfluidics data from complex samples. Finally, possible future directions of Raman-microfluidic systems are presented.
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Affiliation(s)
- Adam F Chrimes
- School of Electrical and Computer Engineering, RMIT University, 124 LaTrobe St, Melbourne, Australia.
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18
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Wang Y, Ou JZ, Balendhran S, Chrimes AF, Mortazavi M, Yao DD, Field MR, Latham K, Bansal V, Friend JR, Zhuiykov S, Medhekar NV, Strano MS, Kalantar-Zadeh K. Electrochemical control of photoluminescence in two-dimensional MoS(2) nanoflakes. ACS Nano 2013; 7:10083-93. [PMID: 24148149 DOI: 10.1021/nn4041987] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenide semiconductors offer unique electronic and optical properties, which are significantly different from their bulk counterparts. It is known that the electronic structure of 2D MoS2, which is the most popular member of the family, depends on the number of layers. Its electronic structure alters dramatically at near atomically thin morphologies, producing strong photoluminescence (PL). Developing processes for controlling the 2D MoS2 PL is essential to efficiently harness many of its optical capabilities. So far, it has been shown that this PL can be electrically or mechanically gated. Here, we introduce an electrochemical approach to actively control the PL of liquid-phase-exfoliated 2D MoS2 nanoflakes by manipulating the amount of intercalated ions including Li(+), Na(+), and K(+) into and out of the 2D crystal structure. These ions are selected as they are crucial components in many bioprocesses. We show that this controlled intercalation allows for large PL modulations. The introduced electrochemically controlled PL will find significant applications in future chemical and bio-optical sensors as well as optical modulators/switches.
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Affiliation(s)
- Yichao Wang
- School of Electrical and Computer Engineering, RMIT University , Melbourne, Victoria, Australia
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19
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Kayani AA, Khoshmanesh K, Nguyen TG, Kostovski G, Chrimes AF, Nasabi M, Heller DA, Mitchell A, Kalantar-zadeh K. Dynamic manipulation of modes in an optical waveguide using dielectrophoresis. Electrophoresis 2012; 33:2075-85. [DOI: 10.1002/elps.201200083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Aminuddin A. Kayani
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Khashayar Khoshmanesh
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Thach G. Nguyen
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Gorgi Kostovski
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Adam F. Chrimes
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Mahyar Nasabi
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Daniel A. Heller
- Department of Chemical Engineering; Massachusetts Institute of Technology; Cambridge; MA; USA
| | - Arnan Mitchell
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
| | - Kourosh Kalantar-zadeh
- School of Electrical and Computer Engineering; RMIT University; Melbourne; Victoria; Australia
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20
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Yi P, Kayani AA, Chrimes AF, Ghorbani K, Nahavandi S, Kalantar-zadeh K, Khoshmanesh K. Thermal analysis of nanofluids in microfluidics using an infrared camera. Lab Chip 2012; 12:2520-2525. [PMID: 22555411 DOI: 10.1039/c2lc40222j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the thermal analysis of liquid containing Al(2)O(3) nanoparticles in a microfluidic platform using an infrared camera. The small dimensions of the microchannel along with the low flow rates (less than 120 μl min(-1)) provide very low Reynolds numbers of less than 17.5, reflecting practical parameters for a microfluidic cooling platform. The heat analysis of nanofluids has never been investigated in such a regime, due to the deficiencies of conventional thermal measurement systems. The infrared camera allows non-contact, three dimensional and high resolution capability for temperature profiling. The system was studied at different w/w concentrations of thermally conductive Al(2)O(3) nanoparticles and the experiments were in excellent agreement with the computational fluid dynamics (CFD) simulations.
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Affiliation(s)
- Pyshar Yi
- RMIT University, School of Electrical and Computer Engineering, Melbourne, Victoria, Australia.
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21
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Chrimes AF, Khoshmanesh K, Stoddart PR, Kayani AA, Mitchell A, Daima H, Bansal V, Kalantar-zadeh K. Active Control of Silver Nanoparticles Spacing Using Dielectrophoresis for Surface-Enhanced Raman Scattering. Anal Chem 2012; 84:4029-35. [DOI: 10.1021/ac203381n] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Adam F. Chrimes
- School of Electrical and Computer
Engineering, RMIT University, Melbourne,
Victoria, Australia
| | - Khashayar Khoshmanesh
- School of Electrical and Computer
Engineering, RMIT University, Melbourne,
Victoria, Australia
| | - Paul R. Stoddart
- Centre
for Atom Optics and Ultrafast
Spectroscopy, Swinburne University, Victoria,
Australia
| | - Aminuddin A. Kayani
- School of Electrical and Computer
Engineering, RMIT University, Melbourne,
Victoria, Australia
| | - Arnan Mitchell
- School of Electrical and Computer
Engineering, RMIT University, Melbourne,
Victoria, Australia
| | - Hemant Daima
- School of Applied
Sciences, RMIT University, Melbourne, Victoria,
Australia
| | - Vipul Bansal
- School of Applied
Sciences, RMIT University, Melbourne, Victoria,
Australia
| | - Kourosh Kalantar-zadeh
- School of Electrical and Computer
Engineering, RMIT University, Melbourne,
Victoria, Australia
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22
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Chrimes AF, Kayani AA, Khoshmanesh K, Stoddart PR, Mulvaney P, Mitchell A, Kalantar-Zadeh K. Dielectrophoresis-Raman spectroscopy system for analysing suspended nanoparticles. Lab Chip 2011; 11:921-8. [PMID: 21267497 DOI: 10.1039/c0lc00481b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A microfluidic dielectrophoresis platform consisting of curved microelectrodes was developed and integrated with a Raman spectroscopy system. The electrodes were patterned on a quartz substrate, which has insignificant Raman response, and integrated with a microfluidic channel that was imprinted in poly-dimethylsiloxane (PDMS). We will show that this novel integrated system can be efficiently used for the determination of suspended particle types and the direct mapping of their spatial concentrations. We will also illustrate the system's unique advantages over conventional optical systems. Nanoparticles of tungsten trioxide (WO(3)) and polystyrene were used in the investigations, as they are Raman active and can be homogeneously suspended in water.
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Affiliation(s)
- Adam F Chrimes
- School of Electrical and Computer Engineering, RMIT University, Victoria, Australia.
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