1
|
Nimbkar S, Leena MM, Moses JA, Anandharamakrishnan C. Microfluidic assessment of nutritional biomarkers: Concepts, approaches and advances. Crit Rev Food Sci Nutr 2022; 64:5113-5127. [PMID: 36503314 DOI: 10.1080/10408398.2022.2150597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Among various approaches to understand the health status of an individual, nutritional biomarkers can provide valuable information, particularly in terms of deficiencies, if any, and their severity. Commonly, the approach revolves around molecular sciences, and the information gained can support prognosis, diagnosis, remediation, and impact assessment of therapies. Microfluidic platforms can offer benefits of low sample and reagent requirements, low cost, high precision, and lower detection limits, with simplicity in handling and the provision for complete automation and integration with information and communication technologies (ICTs). While several advances are being made, this work details the underlying concepts, with emphasis on different point-of-care devices for the analysis of macro and micronutrient biomarkers. In addition, the scope of using different wearable microfluidic sensors for real-time and noninvasive determination of biomarkers is detailed. While several challenges remain, a strong focus is given on recent advances, presenting the state-of-the-art of this field. With more such biomarkers being discovered and commercialization-driven research, trends indicate the wide prospects of this advancing field in supporting clinicians, food technologists, nutritionists, and others.
Collapse
Affiliation(s)
- Shubham Nimbkar
- Computational Modeling and Nanoscale Processing Unit, National Institute of Food Technology, Entrepreneurship and Management, Ministry of Food Processing Industries, Thanjavur, Tamil Nadu, India
| | - M Maria Leena
- Computational Modeling and Nanoscale Processing Unit, National Institute of Food Technology, Entrepreneurship and Management, Ministry of Food Processing Industries, Thanjavur, Tamil Nadu, India
| | - Jeyan Arthur Moses
- Computational Modeling and Nanoscale Processing Unit, National Institute of Food Technology, Entrepreneurship and Management, Ministry of Food Processing Industries, Thanjavur, Tamil Nadu, India
| | - Chinnaswamy Anandharamakrishnan
- Computational Modeling and Nanoscale Processing Unit, National Institute of Food Technology, Entrepreneurship and Management, Ministry of Food Processing Industries, Thanjavur, Tamil Nadu, India
| |
Collapse
|
2
|
Logesh D, Vallikkadan MS, Leena MM, Moses J, Anandharamakrishnan C. Advances in microfluidic systems for the delivery of nutraceutical ingredients. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
3
|
Lertvachirapaiboon C, Baba A, Shinbo K, Kato K. Colorimetric Detection Based on Localized Surface Plasmon Resonance for Determination of Chemicals in Urine. ANAL SCI 2021; 37:929-940. [PMID: 33132235 DOI: 10.2116/analsci.20r005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Colorimetric sensors based on localized surface plasmon resonance (LSPR) have attracted much attention for biosensor and chemical sensor applications. The unique optical effect of LSPR is based on the nanostructure of noble metals (e.g., Au, Ag, and Al) and the refractive index of the environment surrounding these metal nanomaterials. When either the structure or the environment of these nanomaterials is changed, their optical properties change and can be observed by spectroscopic techniques or the naked eye. Colorimetric-probe-based LSPR provides a simple, rapid, real-time, nonlabelled, sensitive biochemical detection and can be used for point-of-care testing as well as rapid screening for the diagnosis of various diseases. Gold and silver nanoparticles, which are the two most widely used plasmonic nanomaterials, demonstrate strong and sensitive LSPR signals that can be used for the selective detection of several chemicals in biochemical compounds provided by the human body (e.g., urine and blood). This information can be used for the diagnosis of several human health conditions. This paper provides information regarding colorimetric probes based on LSPR for the detection of three major chemicals in human urine: creatinine, albumin, and glucose. In addition, the mechanisms of selective detection and quantitative analysis of these chemicals using metal nanoparticles are discussed along with colorimetric-detection-based LSPR for many other specific chemicals that can be detected in urine, such as catecholamine neurotransmitters, thymine, and various medicines. Furthermore, issues regarding the use of portable platforms for health monitoring with colorimetric detection based on LSPR are discussed.
Collapse
Affiliation(s)
| | - Akira Baba
- Graduate School of Science and Technology, Niigata University
| | - Kazunari Shinbo
- Graduate School of Science and Technology, Niigata University
| | - Keizo Kato
- Graduate School of Science and Technology, Niigata University
| |
Collapse
|
4
|
Monia Kabandana GK, Jones CG, Sharifi SK, Chen C. 3D-Printed Microfluidic Devices for Enhanced Online Sampling and Direct Optical Measurements. ACS Sens 2020; 5:2044-2051. [PMID: 32363857 DOI: 10.1021/acssensors.0c00507] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
3D printing has emerged as a robust technique to fabricate reliable and reproducible microfluidic devices. However, a limitation of 3D-printed devices has been the low transparency even when printed in a "clear" material. There are currently no reports regarding direct optical measurements through a 3D-printed device. Here, we present for the first time that the printing orientation can affect the transparency of a 3D-printed object. With the optimal orientation, we printed a microfluidic detector that was sufficiently transparent (transmittance ≈ 80%) for optical quantitation. This finding is significant because it shows the feasibility to directly 3D-print optical components for analytical applications. In addition, we created a novel microfluidic dialysis device via 3D printing, which enabled higher flow rates (for sampling with high temporal resolution) and increased extraction efficiency than commercially available ones. By coupling the microfluidic detector and dialysis probe, we successfully measured the release kinetics of indole from biofilms in a continuous, automated, and near real-time fashion. Indole is an intercellular signaling molecule in biofilms, which may regulate antibiotic resistance. The release kinetics of this molecule had not been quantitated likely because of the lack of a suitable analytical tool. Our results fill this knowledge gap.
Collapse
Affiliation(s)
- Giraso Keza Monia Kabandana
- The Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, United States
| | - Curtis G Jones
- The Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, United States
| | - Sahra Khan Sharifi
- The Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, United States
| | - Chengpeng Chen
- The Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, United States
| |
Collapse
|
5
|
Sun Q, Zheng W, Lin C, Shen D. A Low-Cost Micro-Volume Nephelometric System for Quantitative Immunoagglutination Assays. SENSORS 2019; 19:s19204359. [PMID: 31600932 PMCID: PMC6832725 DOI: 10.3390/s19204359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/29/2019] [Accepted: 10/02/2019] [Indexed: 12/11/2022]
Abstract
Immunoassays have been widely used in scientific research and clinical diagnosis due to their versatile detection capability and high specificity. Immunoagglutination assays are kinds of immunoassay, which can simply and rapidly measure the concentration of analytes. In this work, we developed a low-cost micro-volume nephelometric system for quantitative immunoagglutination assays. We used off-the-shelf components to build the system, and the total cost of key components is only about 20 US dollars. The total detection volume in our system was as low as 3 µL, which could significantly reduce the reagent cost and required sample volume. We further evaluated the system performance via the immunoagglutination assay to measure the concentration of C-reactive protein, a plasma protein with levels rising in response to inflammation. The results demonstrated that our system could measure the concentration of analytes with relatively high sensitivity and precision within four minutes, and has high potential to be applied for clinical diagnostic tests.
Collapse
Affiliation(s)
- Qiqi Sun
- Research Laboratory for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
- Edan Instruments, Inc., Shenzhen 518067, China.
| | - Wei Zheng
- Research Laboratory for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| | - Chao Lin
- Edan Instruments, Inc., Shenzhen 518067, China.
| | | |
Collapse
|
6
|
Microfluidic chip-capillary electrophoresis device for the determination of urinary metabolites and proteins. Bioanalysis 2016; 7:907-22. [PMID: 25932524 DOI: 10.4155/bio.15.26] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Microfluidic chip-CE (MC-CE) devices have caught recent attention for diagnostic applications in urine. This is due to the successes reported in handling real urine samples by integrating microfluidic chips (MC) with analyte enrichment and sample cleanup to CE with high separation efficiency and sensitive analyte detection. Here, we review the determination of urinary metabolites and proteins by MC-CE devices within the past 7 years. The application scope for MC-CE integrated devices was found to exceed the use of either technique alone, showing comparable performance to laser-induced fluorescence detection using less sensitive UV detectors, offering the flexibility to handle difficult urine samples with on-chip dilution and online standard addition and delivering enhanced performance as compared with commercial microfluidic chip electrophoresis chips.
Collapse
|
7
|
Huang CY, Tsai PY, Lee IC, Hsu HY, Huang HY, Fan SK, Yao DJ, Liu CH, Hsu W. A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay. BIOMICROFLUIDICS 2016; 10:011901. [PMID: 26858807 PMCID: PMC4714987 DOI: 10.1063/1.4939942] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/07/2015] [Indexed: 05/04/2023]
Abstract
Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications.
Collapse
Affiliation(s)
- Cheng-Yeh Huang
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
| | - Po-Yen Tsai
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
| | - I-Chin Lee
- Department of Applied Chemistry, National Chiao Tung University , Hsinchu, Taiwan
| | - Hsin-Yun Hsu
- Department of Applied Chemistry, National Chiao Tung University , Hsinchu, Taiwan
| | | | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University , Taipei, Taiwan
| | | | - Cheng-Hsien Liu
- Department of Power Mechanical Engineering, National Tsing Hua University , Hsinchu, Taiwan
| | - Wensyang Hsu
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
| |
Collapse
|
8
|
Coskun AF, Nagi R, Sadeghi K, Phillips S, Ozcan A. Albumin testing in urine using a smart-phone. LAB ON A CHIP 2013; 13:4231-8. [PMID: 23995895 PMCID: PMC3810448 DOI: 10.1039/c3lc50785h] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We demonstrate a digital sensing platform, termed Albumin Tester, running on a smart-phone that images and automatically analyses fluorescent assays confined within disposable test tubes for sensitive and specific detection of albumin in urine. This light-weight and compact Albumin Tester attachment, weighing approximately 148 grams, is mechanically installed on the existing camera unit of a smart-phone, where test and control tubes are inserted from the side and are excited by a battery powered laser diode. This excitation beam, after probing the sample of interest located within the test tube, interacts with the control tube, and the resulting fluorescent emission is collected perpendicular to the direction of the excitation, where the cellphone camera captures the images of the fluorescent tubes through the use of an external plastic lens that is inserted between the sample and the camera lens. The acquired fluorescent images of the sample and control tubes are digitally processed within one second through an Android application running on the same cellphone for quantification of albumin concentration in the urine specimen of interest. Using a simple sample preparation approach which takes ~5 min per test (including the incubation time), we experimentally confirmed the detection limit of our sensing platform as 5-10 μg mL(-1) (which is more than 3 times lower than the clinically accepted normal range) in buffer as well as urine samples. This automated albumin testing tool running on a smart-phone could be useful for early diagnosis of kidney disease or for monitoring of chronic patients, especially those suffering from diabetes, hypertension, and/or cardiovascular diseases.
Collapse
Affiliation(s)
- Ahmet F Coskun
- Electrical Engineering Department, University of California, Los Angeles, CA 90095, USA.
| | | | | | | | | |
Collapse
|
9
|
Li S, Kiehne J, Sinoway LI, Cameron CE, Huang TJ. Microfluidic opportunities in the field of nutrition. LAB ON A CHIP 2013; 13:3993-4003. [PMID: 24056522 PMCID: PMC3875330 DOI: 10.1039/c3lc90090h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Nutrition has always been closely related to human health, which is a constant motivational force driving research in a variety of disciplines. Over the years, the rapidly emerging field of microfluidics has been pushing forward the healthcare industry with the development of microfluidic-based, point-of-care (POC) diagnostic devices. Though a great deal of work has been done in developing microfluidic platforms for disease diagnoses, potential microfluidic applications in the field of nutrition remain largely unexplored. In this Focus article, we would like to investigate the potential chances for microfluidics in the field of nutrition. We will first highlight some of the recent advances in microfluidic blood analysis systems that have the capacity to detect biomarkers of nutrition. Then we will examine existing examples of microfluidic devices for the detection of specific biomarkers of nutrition or nutrient content in food. Finally, we will discuss the challenges in this field and provide some insight into the future of applied microfluidics in nutrition.
Collapse
Affiliation(s)
- Sixing Li
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA. Fax: 814-865-9974; Tel: 814-863-4209;
- Cell and Developmental Biology (CDB) Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Justin Kiehne
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA. Fax: 814-865-9974; Tel: 814-863-4209;
| | - Lawrence I. Sinoway
- Heart and Vascular Institute and Department of Medicine, Penn State College of Medicine, and Milton S. Hershey Medical Center, Hershey, PA, 17033, USA
| | - Craig E. Cameron
- Cell and Developmental Biology (CDB) Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Tony Jun Huang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA. Fax: 814-865-9974; Tel: 814-863-4209;
- Cell and Developmental Biology (CDB) Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
10
|
Hassanzadeh J, Amjadi M, Manzoori JL, Sorouraddin MH. Gold nanorods-enhanced rhodamine B-permanganate chemiluminescence and its analytical application. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 107:296-302. [PMID: 23434557 DOI: 10.1016/j.saa.2013.01.068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 01/19/2013] [Accepted: 01/24/2013] [Indexed: 06/01/2023]
Abstract
A novel enhanced chemiluminescence system was developed by applying gold nanorods (Au NRs) as catalysts in rhodamine B-permanganate reaction. Au NRs with three different aspect ratios were synthesized by seed mediated growth method and characterized by UV-Vis spectra and transmission electron microscopy. It was demonstrated that Au NRs have much higher catalytic effect than spherical nanoparticles on rhodamine B-permanganate chemiluminescence reaction. Among various sizes of Au NRs, those with average aspect ratio of 3.0 were found to have the most remarkable catalytic activity. As an analytical application of the new chemiluminescence system, albumin as a model protein was quantified based on its interaction with NRs. Albumin binds to Au NRs active surfaces and inhibits their catalytic action and therefore decreases the intensity of chemiluminescence. This diminution effect is linearly related to the concentration of the human and bovine serum albumin over the ranges of 0.45-90 and 0.75-123 nmol L(-1), respectively with the corresponding limits of detection of 0.18 and 0.30 nmol L(-1). The method was successfully applied to the determination of albumin in human and bovine serum samples.
Collapse
Affiliation(s)
- Javad Hassanzadeh
- Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 5166616471, Iran
| | | | | | | |
Collapse
|
11
|
CICERI D, NISHI K, STEVENS GW, PERERA JM. An Integrated UV-Vis Microfluidic Device for the Study of Concentrated Solvent Extraction Reactions. SOLVENT EXTRACTION RESEARCH AND DEVELOPMENT-JAPAN 2013. [DOI: 10.15261/serdj.20.197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Davide CICERI
- Department of Chemical and Biomolecular Engineering, The University of Melbourne
| | - Kazuiko NISHI
- Division of Materials Science and Chemical Engineering, Faculty of Engineering, Yokohama National University
| | - Geoffrey W. STEVENS
- Department of Chemical and Biomolecular Engineering, The University of Melbourne
| | - Jilska M. PERERA
- Department of Chemical and Biomolecular Engineering, The University of Melbourne
| |
Collapse
|
12
|
Meibodi ESA, Azizi MD, Paknejad M, Larijani B, Omidfar K. Development of an enhanced chemiluminescence immunoassay (CLIA) for detecting urinary albumin. Mol Biol Rep 2012; 39:10851-8. [DOI: 10.1007/s11033-012-1981-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 10/01/2012] [Indexed: 01/02/2023]
|
13
|
Vashist SK, Saraswat M, Holthšfer H. Comparative Study of the Developed Chemiluminescent, ELISA and SPR Immunoassay Formats for the Highly Sensitive Detection of Human Albumin. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proche.2012.10.145] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Lin CC, Tseng CC, Chuang TK, Lee DS, Lee GB. Urine analysis in microfluidic devices. Analyst 2011; 136:2669-88. [PMID: 21617803 DOI: 10.1039/c1an15029d] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Microfluidics has attracted considerable attention since its early development in the 1980s and has experienced rapid growth in the past three decades due to advantages associated with miniaturization, integration and automation. Urine analysis is a common, fast and inexpensive clinical diagnostic tool in health care. In this article, we will be reviewing recent works starting from 2005 to the present for urine analysis using microfluidic devices or systems and to provide in-depth commentary about these techniques. Moreover, commercial strips that are often treated as chips and their readers for urine analysis will also be briefly discussed. We start with an introduction to the physiological significance of various components or measurement standards in urine analysis, followed by a brief introduction to enabling microfluidic technologies. Then, microfluidic devices or systems for sample pretreatments and for sensing urinary macromolecules, micromolecules, as well as multiplexed analysis are reviewed, in this sequence. Moreover, a microfluidic chip for urinary proteome profiling is also discussed, followed by a section discussing commercial products. Finally, the authors' perspectives on microfluidic-based urine analysis are provided. These advancements in microfluidic techniques for urine analysis may improve current routine clinical practices, particularly for point-of-care (POC) applications.
Collapse
Affiliation(s)
- Chun-Che Lin
- Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan
| | | | | | | | | |
Collapse
|
15
|
Boonyasit Y, Maturos T, Sappat A, Jomphoak A, Tuantranont A, Laiwattanapaisal W. Passive micromixer integration with a microfluidic chip for calcium assay based on the arsenazo III method. BIOCHIP JOURNAL 2011. [DOI: 10.1007/s13206-011-5101-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
16
|
Pereira AT, Novo P, Prazeres DMF, Chu V, Conde JP. Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes. BIOMICROFLUIDICS 2011; 5:14102. [PMID: 21403847 PMCID: PMC3055902 DOI: 10.1063/1.3553014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 01/07/2011] [Indexed: 05/09/2023]
Abstract
Miniaturization of immunoassays through microfluidic technology has the potential to decrease the time and the quantity of reactants required for analysis, together with the potential of achieving multiplexing and portability. A lab-on-chip system incorporating a thin-film amorphous silicon (a-Si:H) photodiode microfabricated on a glass substrate with a thin-film amorphous silicon-carbon alloy directly deposited above the photodiode and acting as a fluorescence filter is integrated with a polydimethylsiloxane-based microfluidic network for the direct detection of antibody-antigen molecular recognition reactions using fluorescence. The model immunoassay used consists of primary antibody adsorption to the microchannel walls followed by its recognition by a secondary antibody labeled with a fluorescent quantum-dot tag. The conditions for the flow-through analysis in the microfluidic format were defined and the total assay time was 30 min. Specific molecular recognition was quantitatively detected. The measurements made with the a-Si:H photodiode are consistent with that obtained with a fluorescence microscope and both show a linear dependence on the antibody concentration in the nanomolar-micromolar range.
Collapse
|
17
|
Abstract
Plasma volume expanders comprise a heterogeneous group of substances used in medicine that are intravenously administered in cases of great blood loss owing to surgery or medical emergency. These substances, however, can also be used to artificially enhance performance of healthy athletes in sport activities, and to mask the presence of others substances. These practices are considered doping, and are therefore prohibited by the International Olympic Committee and the World Antidoping Agency. Consequently, drug testing procedures are essential. The present work provides an overview of plasma volume expanders, assembling pertinent data such as chemical characteristics, physiological aspects, adverse effects, doping and analytical detection methods, which are currently dispersed in the literature.
Collapse
|