1
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Structural view of insulin adsorption on the multiple sizes of Cu nanoparticles; molecular dynamics simulation study. Arch Biochem Biophys 2022; 722:109219. [DOI: 10.1016/j.abb.2022.109219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/08/2022] [Accepted: 04/09/2022] [Indexed: 11/19/2022]
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2
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Malekzad H, Zangabad PS, Mohammadi H, Sadroddini M, Jafari Z, Mahlooji N, Abbaspour S, Gholami S, Ghanbarpoor M, Pashazadeh R, Beyzavi A, Karimi M, Hamblin MR. Noble metal nanostructures in optical biosensors: Basics, and their introduction to anti-doping detection. Trends Analyt Chem 2018; 100:116-135. [PMID: 29731530 PMCID: PMC5933885 DOI: 10.1016/j.trac.2017.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nanotechnology has illustrated significant potentials in biomolecular-sensing applications; particularly its introduction to anti-doping detection is of great importance. Illicit recreational drugs, substances that can be potentially abused, and drugs with dosage limitations according to the prohibited lists announced by the World Antidoping Agency (WADA) are becoming of increasing interest to forensic chemists. In this review, the theoretical principles of optical biosensors based on noble metal nanoparticles, and the transduction mechanism of commonly-applied plasmonic biosensors are covered. We review different classes of recently-developed plasmonic biosensors for analytic determination and quantification of illicit drugs in anti-doping applications. The important classes of illicit drugs include anabolic steroids, opioids, stimulants, and peptide hormones. The main emphasis is on the advantages that noble metal nano-particles bring to optical biosensors for signal enhancement and the development of highly sensitive (label-free) biosensors. In the near future, such optical biosensors may be an invaluable substitute for conventional anti-doping detection methods such as chromatography-based approaches, and may even be commercialized for routine anti-doping tests.
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Affiliation(s)
- Hedieh Malekzad
- Advanced Nanobiotechnology and Nanomedicine Research Group (ANNRG), Iran
| | - Parham Sahandi Zangabad
- Research Center for Pharmaceutical Nanotechnology (RCPN), Tabriz University of Medical Science (TUOMS), Tabriz, Iran
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
- Bio-Nano-Interfaces: Convergence of Sciences (BNICS), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Nanomedicine Research Association (NRA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Department of Medical Nanotechnology, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Hadi Mohammadi
- Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
| | - Mohsen Sadroddini
- Polymer Engineering Department, Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Zahra Jafari
- Department of Food Science and Technology, College of Agriculture and Food Science, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran
| | - Niloofar Mahlooji
- Department of Chemistry, Semnan University, Semnan 35351-19111, Iran
| | - Somaye Abbaspour
- School of Science and Engineering, Sharif University of Technology, International Campus, Iran
| | | | | | - Rahim Pashazadeh
- Advanced Nanobiotechnology and Nanomedicine Research Group (ANNRG), Iran
| | - Ali Beyzavi
- Koch Institute of MIT, 500 Main Street, Cambridge MA, USA
| | - Mahdi Karimi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
- Department of Medical Nanotechnology, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
- Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Applied Biotechnology Research Center, Teheran Medical Sciences Branch, Islamic Azad University, Tehran Iran
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Michael R Hamblin
- Applied Biotechnology Research Center, Teheran Medical Sciences Branch, Islamic Azad University, Tehran Iran
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA
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3
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Matsuda R, Rodriguez E, Suresh D, Hage DS. Chromatographic immunoassays: strategies and recent developments in the analysis of drugs and biological agents. Bioanalysis 2015; 7:2947-66. [PMID: 26571109 PMCID: PMC4820777 DOI: 10.4155/bio.15.206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A chromatographic immunoassay is a technique in which an antibody or antibody-related agent is used as part of a chromatographic system for the isolation or measurement of a specific target. Various binding agents, detection methods, supports and assay formats have been developed for this group of methods, and applications have been reported that range from drugs, hormones and herbicides to peptides, proteins and bacteria. This review discusses the general principles and applications of chromatographic immunoassays, with an emphasis being given to methods and formats that have been developed for the analysis of drugs and biological agents. The relative advantages or limitations of each format are discussed. Recent developments and research in this field, as well as possible future directions, are also considered.
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Affiliation(s)
- Ryan Matsuda
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA
| | - Elliott Rodriguez
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA
| | - Doddavenkatanna Suresh
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA
- Home Department: Department of Chemistry, Tumkur University, Tumkur, Karnataka 572103, India
| | - David S Hage
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA
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4
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Chaloupka K, Malam Y, Seifalian AM. Nanosilver as a new generation of nanoproduct in biomedical applications. Trends Biotechnol 2010; 28:580-8. [PMID: 20724010 DOI: 10.1016/j.tibtech.2010.07.006] [Citation(s) in RCA: 763] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2010] [Revised: 07/14/2010] [Accepted: 07/19/2010] [Indexed: 02/06/2023]
Abstract
Nanosilver (NS), comprising silver nanoparticles, is attracting interest for a range of biomedical applications owing to its potent antibacterial activity. It has recently been demonstrated that NS has useful anti-inflammatory effects and improves wound healing, which could be exploited in developing better dressings for wounds and burns. The key to its broad-acting and potent antibacterial activity is the multifaceted mechanism by which NS acts on microbes. This is utilized in antibacterial coatings on medical devices to reduce nosocomial infection rates. Many new synthesis methods have emerged and are being evaluated for NS production for medical applications. NS toxicity is also critically discussed to reflect on potential concerns before widespread application in the medical field.
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Affiliation(s)
- Karla Chaloupka
- Centre for Nanotechnology & Regenerative Medicine, Division of Surgery & Interventional Science, University College London, London, UK
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5
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Szmacinski H, Murtaza Z, Lakowicz JR. Time-Resolved Fluorometric Method for One-Step Immunoassays Using Plasmonic Nanostructures. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2010; 114:7236-7241. [PMID: 20556227 PMCID: PMC2885785 DOI: 10.1021/jp906743m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Affiliation(s)
- Henryk Szmacinski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland Baltimore, 725 W. Lombard St., Baltimore, MD, 21201
| | - Zakir Murtaza
- Pierce Biotechnology, Inc., 3747 N. Meridian Rd., Rockford, IL, 61101
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland Baltimore, 725 W. Lombard St., Baltimore, MD, 21201
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6
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Enhancing the analytical performance of immunoassays that employ metal-enhanced fluorescence. Anal Bioanal Chem 2009; 396:1127-34. [DOI: 10.1007/s00216-009-3357-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/20/2009] [Accepted: 11/23/2009] [Indexed: 11/26/2022]
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7
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McDonagh C, Stranik O, Nooney R, MacCraith BD. Nanoparticle strategies for enhancing the sensitivity of fluorescence-based biochips. Nanomedicine (Lond) 2009; 4:645-56. [DOI: 10.2217/nnm.09.48] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
This article describes strategies for achieving fluorescence enhancement in optical biochips. Two strategies are discussed: plasmonic enhancement, which is due to the localized surface plasmon resonance of metal nanostructures that are adjacent to the fluorescent labels in optical immunoassays; and the use of high-brightness silica nanoparticles as enhanced labels. We present a review of the state-of-the-art in both areas, including synthesis techniques for the metal and silica nanoparticles and the use of the nanoparticles in optical immunoassays. Data are presented that highlight the key design parameters which influence the level of enhancement and model assay data are presented that illustrate potential enhancements in assay performance.
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Affiliation(s)
- Colette McDonagh
- Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Ondrej Stranik
- Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Robert Nooney
- Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Brian D MacCraith
- Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
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8
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Gryczynski I, Matveeva E, Sarkar P, Bharill S, Borejdo J, Mandecki W, Akopova I, Gryczynski Z. Metal Enhanced Fluorescence on Silicon Wafer Substrates. Chem Phys Lett 2008; 462:327-330. [PMID: 19137060 PMCID: PMC2575380 DOI: 10.1016/j.cplett.2008.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We report on the fluorescence enhancement induced by silver island film (SIF) deposited on a silicon wafer. The model immunoassay was studied on silvered and unsilvered wafers. The fluorescence brightness of Rhodamine Red X increased about 300% on the SIF, while the lifetime was reduced by several fold and the photostability increased substantially. We discuss potential uses of silicon wafer substrates in multiplex assays in which the fluorescence is enhanced due to the SIF, and the multiplexing is achieved by using micro transponders.
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Affiliation(s)
- I. Gryczynski
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
- Dept. of Cell Biology and Genetics, UNTHSC, Fort Worth, TX 76107
| | - E.G. Matveeva
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
| | - P. Sarkar
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
| | - S. Bharill
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
| | - J. Borejdo
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
| | - W. Mandecki
- PharmaSeq, Inc., 11 Deer Park Dr., Suite 104, Monmouth Jct., NJ 08852
| | - I. Akopova
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
| | - Z. Gryczynski
- Center for Commercialization of Fluorescence Technologies, Dept. of Molecular Biology and Immunology, UNTHSC, Fort Worth, TX 76107
- Dept. of Cell Biology and Genetics, UNTHSC, Fort Worth, TX 76107
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9
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Mitamura K, Imae T, Tian S, Knoll W. Surface plasmon fluorescence investigation of energy-transfer-controllable organic thin films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:2266-2270. [PMID: 18275229 DOI: 10.1021/la703001y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Thin functional organic films on a gold substrate were fabricated by adsorbing tetrakis(carboxyphenyl)porphyrin (TCPP) on a spacer layer, which was prepared by the layer-by-layer adsorption of a dendrimer and a linear polymer. The thickness and photoluminescence of the films were investigated by surface plasmon resonance and surface plasmon fluorescence techniques, respectively. TCPP adsorbed on the spacer layer in aqueous solutions of different ionic strengths resulted in a thick TCPP adlayer at high ionic strength and a shrunk spacer layer at low ionic strength. The fluorescence was quenched at high ionic strength but could be observed at low ionic strength. The effects are explained by the states of dye aggregation. This study shows the control of energy transfer from a metal surface to a dye layer by changing the dye adlayer. It can contribute to the development of molecular devices involving energy-transfer systems.
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Affiliation(s)
- Koji Mitamura
- Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
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10
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Matveeva EG, Shtoyko T, Gryczynski I, Akopova I, Gryczynski Z. Fluorescence Quenching/Enhancement Surface Assays: Signal Manipulation Using Silver-coated Gold Nanoparticles. Chem Phys Lett 2008; 454:85-90. [PMID: 19279673 DOI: 10.1016/j.cplett.2008.01.075] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Gold nanoparticles covalently attached to the indium tin oxide coated glass slide drastically quench fluorescence of a surface immunoassay (approximately 5-fold). Silver electrochemically deposited over the gold particles leads to fluorescence amplification: signal increases approximately 7-8 times if compared to the signal on gold particles not covered with silver. This phenomenon allows enhancing of the surface immunoassays utilizing both types of nanoparticles.
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Affiliation(s)
- Evgenia G Matveeva
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology; Department of Cell Biology and Genetics, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76106, USA
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11
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Jiang Z, Chen Y, Liang A, Tao H, Tang N, Zhong F. Silver nanoparticle labeled immunoresonance scattering spectral assay for trace fibrinogen. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/s11426-007-0064-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Yamaguchi T, Kaya T, Takei H. Characterization of cap-shaped silver particles for surface-enhanced fluorescence effects. Anal Biochem 2007; 364:171-9. [PMID: 17400167 DOI: 10.1016/j.ab.2007.02.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 02/19/2007] [Accepted: 02/21/2007] [Indexed: 10/23/2022]
Abstract
Surface-enhanced fluorescence has potentially many desirable properties as an analytical method for medical diagnostics, but the effect observed so far is rather modest and only in conjunction with fluorophores with low quantum yields. Coupled with the fact that preparation of suitable surfaces at low costs has been difficult, this has limited its utilities. Here we report a novel method for forming uniform and reproducible surfaces with respectable enhancement ratios even for high-quantum-yield fluorophores. Formation of dense surface-adsorbed latex spheres on a flat surface via partial aggregation, followed by evaporation of silver, results in a film consisting of cap-shaped silver particles at high densities. Binding of fluorescence biomolecules, either through physisorption or antigen-antibody reaction, was performed, and enhancements close to 50 have been observed with fluorophores such as R-phycoerythrin and Alexa 546-labeled, bovine serum albumin, both of which have quantum yields around 0.8. We attribute this to the unique shape of the silver particle and the presence of abundant gaps among adjacent particles at high densities. The effectiveness of the new surface is also demonstrated with IL-6 sandwich assays.
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13
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Gobi KV, Iwasaka H, Miura N. Self-assembled PEG monolayer based SPR immunosensor for label-free detection of insulin. Biosens Bioelectron 2007; 22:1382-9. [PMID: 16870423 DOI: 10.1016/j.bios.2006.06.012] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Revised: 06/08/2006] [Accepted: 06/15/2006] [Indexed: 11/26/2022]
Abstract
A simple and rapid continuous-flow immunosensor based on surface plasmon resonance (SPR) has been developed for detection of insulin as low as 1 ng ml-1 (ppb) with a response time of less than 5 min. At first, a heterobifunctional oligo(ethyleneglycol)-dithiocarboxylic acid derivative (OEG-DCA) containing dithiol and carboxyl end groups was used to functionalize the thin Au-film of SPR chip. Insulin was covalently bound to the Au-thiolate monolayer of OEG-DCA for activating the sensor surface to immunoaffinity interactions. An on-line competitive immunosensing principle is examined for detection of insulin, in which the direct affinity binding of anti-insulin antibody to the insulin on sensor surface is examined in the presence and absence of various concentrations of insulin. Immunoreaction of anti-insulin antibody with the sensor surface was optimized with reference to antibody concentration, sample analysis time and flow-rate to provide the desired detection limit and determination range. With the immunosensor developed, the lowest detectable concentration of insulin is 1 ng ml-1 and the determination range covers a wide concentration of 1-300 ng ml-1. The developed OEG-monolayer based sensor chip exhibited high resistance to non-specific adsorption of proteins, and an uninterrupted highly sensitive detection of insulin from insulin-impregnated serum samples has been demonstrated. After an immunoreaction cycle, active sensor surface was regenerated simply by a brief flow of an acidic buffer (glycine.HCl; pH 2.0) for less than 1 min. A same sensor chip was found reusable for more than 25 cycles without an appreciable change in the original sensor activity.
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Affiliation(s)
- K Vengatajalabathy Gobi
- Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
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14
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Katz E, Willner I. Integrated nanoparticle-biomolecule hybrid systems: synthesis, properties, and applications. Angew Chem Int Ed Engl 2005; 43:6042-108. [PMID: 15538757 DOI: 10.1002/anie.200400651] [Citation(s) in RCA: 1630] [Impact Index Per Article: 85.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nanomaterials, such as metal or semiconductor nanoparticles and nanorods, exhibit similar dimensions to those of biomolecules, such as proteins (enzymes, antigens, antibodies) or DNA. The integration of nanoparticles, which exhibit unique electronic, photonic, and catalytic properties, with biomaterials, which display unique recognition, catalytic, and inhibition properties, yields novel hybrid nanobiomaterials of synergetic properties and functions. This review describes recent advances in the synthesis of biomolecule-nanoparticle/nanorod hybrid systems and the application of such assemblies in the generation of 2D and 3D ordered structures in solutions and on surfaces. Particular emphasis is directed to the use of biomolecule-nanoparticle (metallic or semiconductive) assemblies for bioanalytical applications and for the fabrication of bioelectronic devices.
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Affiliation(s)
- Eugenii Katz
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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15
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Matveeva EG, Gryczynski Z, Lakowicz JR. Myoglobin immunoassay based on metal particle-enhanced fluorescence. J Immunol Methods 2005; 302:26-35. [PMID: 15996681 PMCID: PMC6816259 DOI: 10.1016/j.jim.2005.04.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Revised: 04/11/2005] [Accepted: 04/18/2005] [Indexed: 11/30/2022]
Abstract
Enhanced fluorescence on silver island films (SIFs) is utilized to develop a sandwich-format immunoassay for the cardiac marker myoglobin (Myo). Myoglobin was first captured on surfaces coated with anti-Myo antibodies; the surface was then incubated with fluorescently labeled anti-Myo antibodies. The system was examined on glass surfaces and on SIFs. We observed the enhancement of the signal from SIFs in the range of 10-15-fold if compared to the signal from the glass substrate not modified with a SIF. A kinetic immunoassay for Myo on SIF-modified surface results in a decreased background signal. The initial results show that it is possible to detect Myoglobin concentrations below 50 ng/mL, which is lower than clinical cut-off for Myoglobin in healthy patients. We suggest the use of SIF-modified substrates for increasing the sensitivity of surface assays with fluorescence detection.
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Affiliation(s)
- Evgenia G Matveeva
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore Medical School, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, MD 21201, USA.
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16
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Matveeva E, Gryczynski Z, Malicka J, Gryczynski I, Lakowicz JR. Metal-enhanced fluorescence immunoassays using total internal reflection and silver island-coated surfaces. Anal Biochem 2005; 334:303-11. [PMID: 15494138 PMCID: PMC6853062 DOI: 10.1016/j.ab.2004.08.034] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Indexed: 12/27/2022]
Abstract
We present a generic immunoassay platform that uses enhanced total internal reflection fluorescence in the proximity of silver island films (SIFs), a surface coating consisting of metal (silver) particles. This platform is used with a model immunoassay where a protein antigen, rabbit immunoglobulin G, was immobilized on the SIF-coated glass surface. The signal from a fluorescent dye-labeled anti-rabbit antibody binding to the surface antigen was detected; different color dyes have been tested. Close placement of the fluorophore to surface-bound silver nanostructures results in dramatic signal enhancement (up to 40-fold) on the SIFs as compared with the glass slides. Use of the total internal reflection mode of excitation has significant advantages (over classic front-face excitation) for practical assay development. The limited evanescent wave excitation volume makes it possible to minimize the background signal and use the immunoassay with no need for any washing steps.
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17
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Katz E, Willner I. Integrierte Hybridsysteme aus Nanopartikeln und Biomolekülen: Synthese, Eigenschaften und Anwendungen. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200400651] [Citation(s) in RCA: 256] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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