1
|
Lim AE, Lam YC. Electroosmotic Flow Hysteresis for Fluids with Dissimilar pH and Ionic Species. MICROMACHINES 2021; 12:mi12091031. [PMID: 34577675 PMCID: PMC8467362 DOI: 10.3390/mi12091031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/21/2021] [Accepted: 08/26/2021] [Indexed: 12/15/2022]
Abstract
Electroosmotic flow (EOF) involving displacement of multiple fluids is employed in micro-/nanofluidic applications. There are existing investigations on EOF hysteresis, i.e., flow direction-dependent behavior. However, none so far have studied the solution pair system of dissimilar ionic species with substantial pH difference. They exhibit complicated hysteretic phenomena. In this study, we investigate the EOF of sodium bicarbonate (NaHCO3, alkaline) and sodium chloride (NaCl, slightly acidic) solution pair via current monitoring technique. A developed slip velocity model with a modified wall condition is implemented with finite element simulations. Quantitative agreements between experimental and simulation results are obtained. Concentration evolutions of NaHCO3-NaCl follow the dissimilar anion species system. When NaCl displaces NaHCO3, EOF reduces due to the displacement of NaHCO3 with high pH (high absolute zeta potential). Consequently, NaCl is not fully displaced into the microchannel. When NaHCO3 displaces NaCl, NaHCO3 cannot displace into the microchannel as NaCl with low pH (low absolute zeta potential) produces slow EOF. These behaviors are independent of the applied electric field. However, complete displacement tends to be achieved by lowering the NaCl concentration, i.e., increasing its zeta potential. In contrast, the NaHCO3 concentration has little impact on the displacement process. These findings enhance the understanding of EOF involving solutions with dissimilar pH and ion species.
Collapse
|
2
|
Xie Z, Pu H, Sun DW. Computer simulation of submicron fluid flows in microfluidic chips and their applications in food analysis. Compr Rev Food Sci Food Saf 2021; 20:3818-3837. [PMID: 34056852 DOI: 10.1111/1541-4337.12766] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/24/2021] [Accepted: 04/15/2021] [Indexed: 01/01/2023]
Abstract
In recent years, countries around the world have maintained a zero-tolerance attitude toward safety problems in the food industry. In order to ensure human health, a fast, sensitive, and high-throughput analysis of food contaminants is necessary to ensure safe food products on the market. Microfluidics, as a high-efficiency and sensitive detection technology, has many advantages in the detection of food contaminants, including foodborne pathogens, pesticides, heavy metal ions, toxic substances, and so forth, especially in conjunction with a variety of submicron fluid driving methods, making food detection and analysis more efficient and accurate. This review introduces the principle of submicron fluid driving modes and discusses the driving simulation of submicron fluid in microfluidic chips. In addition, the latest developments in the application of simulation in food analysis from 2006 to 2020 are discussed, and the computer simulation of submicron fluid flow in microfluidic chips and its application and development trend in food analysis are also highlighted. The review indicates that microfluidic technology, using numerical simulation as an auxiliary tool, combined with traditional methods has greatly improved the detection and analysis of food products. In addition, microfluidics combined with a variety of control methods embodies the ability of specific, multifunctional, and sensitive detection and analysis of food products. The development of high-sensitivity, high-throughput, portable, integrated microfluidic chips will enable the technology to be applied in practice.
Collapse
Affiliation(s)
- Zhaoda Xie
- School of Mechanical and Electrical Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, China
| | - Hongbin Pu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China.,Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, China.,Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou, China
| | - Da-Wen Sun
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China.,Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, China.,Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou, China.,Food Refrigeration and Computerized Food Technology, School of Agriculture and Food Science Centre, University College Dublin, National University of Ireland, Dublin, Ireland
| |
Collapse
|
3
|
Numerical Investigation of Nanostructure Orientation on Electroosmotic Flow. MICROMACHINES 2020; 11:mi11110971. [PMID: 33138301 PMCID: PMC7694110 DOI: 10.3390/mi11110971] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 10/28/2020] [Accepted: 10/28/2020] [Indexed: 12/18/2022]
Abstract
Electroosmotic flow (EOF) is fluid flow induced by an applied electric field, which has been widely employed in various micro-/nanofluidic applications. Past investigations have revealed that the presence of nanostructures in microchannel reduces EOF. Hitherto, the angle-dependent behavior of nanoline structures on EOF has not yet been studied in detail and its understanding is lacking. Numerical analyses of the effect of nanoline orientation angle θ on EOF to reveal the associated mechanisms were conducted in this investigation. When θ increases from 5° to 90° (from parallel to perpendicular to the flow direction), the average EOF velocity decreases exponentially due to the increase in distortion of the applied electric field distribution at the structured surface, as a result of the increased apparent nanolines per unit microchannel length. With increasing nanoline width W, the decrease of average EOF velocity is fairly linear, attributed to the simultaneous narrowing of nanoline ridge (high local fluid velocity region). While increasing nanoline depth D results in a monotonic decrease of the average EOF velocity. This reduction stabilizes for aspect ratio D/W > 0.5 as the electric field distribution distortion within the nanoline trench remains nearly constant. This investigation reveals that the effects on EOF of nanolines, and by extrapolation for any nanostructures, may be directly attributed to their effects on the distortion of the applied electric field distribution within a microchannel.
Collapse
|
4
|
Ge P, Wang S, Liu Y, Liu W, Yu N, Zhang J, Shen H, Zhang J, Yang B. Autonomous Control of Fluids in a Wide Surface Tension Range in Microfluidics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7248-7255. [PMID: 28681601 DOI: 10.1021/acs.langmuir.7b01934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this paper, we report the preparation of anisotropic wetting surfaces that could control various wetting behaviors of liquids in a wide surface tension range (from water to oil), which could be employed as a platform for controlling the flow of liquids in microfluidics (MFs). The anisotropic wetting surfaces are chemistry-asymmetric "Janus" silicon cylinder arrays, which are fabricated via selecting and regulating the functional groups on the surface of each cylinder unit. Liquids (in a wide surface tension range) wet in a unidirectional manner along the direction that was modified by the group with large surface energy. Through introducing the Janus structure into a T-shaped pattern and integrating it with an identical T-shaped poly(dimethylsiloxane) microchannel, the as-prepared chips can be utilized to perform as a surface tension admeasuring apparatus or a one-way valve for liquids in a wide surface tension range, even oil. Furthermore, because of the excellent ability in controlling the flowing behavior of liquids in a wide surface tension range in an open system or a microchannel, the anisotropic wetting surfaces are potential candidates to be applied both in open MFs and conventional MFs, which would broaden the application fields of MFs.
Collapse
Affiliation(s)
- Peng Ge
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Shuli Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Yongshun Liu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences , Changchun 130033, P. R. China
| | - Wendong Liu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Nianzuo Yu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Jianglei Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Huaizhong Shen
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Junhu Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| | - Bai Yang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, P. R. China
| |
Collapse
|
5
|
Medawar V, Messina GA, Fernández-Baldo M, Raba J, Pereira SV. Fluorescent immunosensor using AP-SNs and QDs for quantitation of IgG anti- Toxocara canis. Microchem J 2017. [DOI: 10.1016/j.microc.2016.10.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
6
|
Development of quantum dots-based biosensor towards on-farm detection of subclinical ketosis. Biosens Bioelectron 2015; 72:140-7. [PMID: 25978442 DOI: 10.1016/j.bios.2015.05.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/05/2015] [Indexed: 11/23/2022]
Abstract
Early detection of dairy animal health issues allows the producer or veterinarian to intervene before the animals' production levels, or even survival, is threatened. An increased concentration of β-hydroxybutyrate (βHBA) is a key biomarker for diagnosis of subclinical ketosis (SCK), and provides information on the health stress in cows well before any external symptoms are observable. In this study, quantum dots (QDs) modified with cofactor nicotinamide adenine dinucleotide (NAD(+)) were prepared for the sensing event, by which the βHBA concentration in the cow's blood and milk samples was determined via fluorescence analysis of the functionalized QDs. The detection was performed on a custom designed microfluidic platform combining with a low cost and miniaturized optical sensor. The sensing mechanism was first validated by a microplate reader method and then applied to the microfluidic platform. Standard βHBA solution, βHBA in blood and milk samples from cows were successfully measured by this novel technology with a detection limit at a level of 35 µM. Side by side comparison of the developed microfluidic biosensor with a commercial kit presented its good performance.
Collapse
|
7
|
Hommatsu M, Okahashi H, Ohta K, Tamai Y, Tsukagoshi K, Hashimoto M. Development of a PCR/LDR/flow-through hybridization assay using a capillary tube, probe DNA-immobilized magnetic beads and chemiluminescence detection. ANAL SCI 2013; 29:689-95. [PMID: 23842410 DOI: 10.2116/analsci.29.689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A polymerase chain reaction (PCR)/ligase detection reaction (LDR)/flow-through hybridization assay using chemiluminescence (CL) detection was developed for analyzing point mutations in gene fragments with high diagnostic value for colorectal cancers. A flow-through hybridization format using a capillary tube, in which probe DNA-immobilized magnetic beads were packed, provided accelerated hybridization kinetics of target DNA (i.e. LDR product) to the probe DNA. Simple fluid manipulations enabled both allele-specific hybridization and the removal of non-specifically bound DNA in the wash step. Furthermore, the use of CL detection greatly simplified the detection scheme, since CL does not require a light source for excitation of the fluorescent dye tags on the LDR products. Preliminary results demonstrated that this analytical system could detect both homozygous and heterozygous mutations, without the expensive instrumentation and cumbersome procedures required by conventional DNA microarray-based methods.
Collapse
Affiliation(s)
- Manami Hommatsu
- Department of Chemical Engineering and Materials Science, Faculty of Science and Engineering, Doshisha University, Kyotanabe, Kyoto, Japan
| | | | | | | | | | | |
Collapse
|
8
|
Foudeh AM, Fatanat Didar T, Veres T, Tabrizian M. Microfluidic designs and techniques using lab-on-a-chip devices for pathogen detection for point-of-care diagnostics. LAB ON A CHIP 2012; 12:3249-66. [PMID: 22859057 DOI: 10.1039/c2lc40630f] [Citation(s) in RCA: 267] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Effective pathogen detection is an essential prerequisite for the prevention and treatment of infectious diseases. Despite recent advances in biosensors, infectious diseases remain a major cause of illnesses and mortality throughout the world. For instance in developing countries, infectious diseases account for over half of the mortality rate. Pathogen detection platforms provide a fundamental tool in different fields including clinical diagnostics, pathology, drug discovery, clinical research, disease outbreaks, and food safety. Microfluidic lab-on-a-chip (LOC) devices offer many advantages for pathogen detection such as miniaturization, small sample volume, portability, rapid detection time and point-of-care diagnosis. This review paper outlines recent microfluidic based devices and LOC design strategies for pathogen detection with the main focus on the integration of different techniques that led to the development of sample-to-result devices. Several examples of recently developed devices are presented along with respective advantages and limitations of each design. Progresses made in biomarkers, sample preparation, amplification and fluid handling techniques using microfluidic platforms are also covered and strategies for multiplexing and high-throughput analysis, as well as point-of-care diagnosis, are discussed.
Collapse
Affiliation(s)
- Amir M Foudeh
- Biomedical Engineering Department, McGill University, Montreal, QC H3A 2B4, Canada
| | | | | | | |
Collapse
|
9
|
Weng X, Jiang H, Li D. Electrokinetically-controlled RNA-DNA hybridization assay for foodborne pathogens. Mikrochim Acta 2012. [DOI: 10.1007/s00604-012-0853-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|