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An electrophoresis approach with online thermal lens detection to monitoring DNA surface coatings on gold nanoparticles. Microchem J 2022. [DOI: 10.1016/j.microc.2021.106961] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Stawicki CM, Rinker TE, Burns M, Tonapi SS, Galimidi RP, Anumala D, Robinson JK, Klein JS, Mallick P. Modular fluorescent nanoparticle DNA probes for detection of peptides and proteins. Sci Rep 2021; 11:19921. [PMID: 34620912 PMCID: PMC8497506 DOI: 10.1038/s41598-021-99084-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023] Open
Abstract
Fluorescently labeled antibody and aptamer probes are used in biological studies to characterize binding interactions, measure concentrations of analytes, and sort cells. Fluorescent nanoparticle labels offer an excellent alternative to standard fluorescent labeling strategies due to their enhanced brightness, stability and multivalency; however, challenges in functionalization and characterization have impeded their use. This work introduces a straightforward approach for preparation of fluorescent nanoparticle probes using commercially available reagents and common laboratory equipment. Fluorescent polystyrene nanoparticles, Thermo Fisher Scientific FluoSpheres, were used in these proof-of-principle studies. Particle passivation was achieved by covalent attachment of amine-PEG-azide to carboxylated particles, neutralizing the surface charge from - 43 to - 15 mV. A conjugation-annealing handle and DNA aptamer probe were attached to the azide-PEG nanoparticle surface either through reaction of pre-annealed handle and probe or through a stepwise reaction of the nanoparticles with the handle followed by aptamer annealing. Nanoparticles functionalized with DNA aptamers targeting histidine tags and VEGF protein had high affinity (EC50s ranging from 3 to 12 nM) and specificity, and were more stable than conventional labels. This protocol for preparation of nanoparticle probes relies solely on commercially available reagents and common equipment, breaking down the barriers to use nanoparticles in biological experiments.
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Affiliation(s)
| | - Torri E Rinker
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA.
| | - Markus Burns
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Sonal S Tonapi
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Rachel P Galimidi
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Deepthi Anumala
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Julia K Robinson
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Joshua S Klein
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
| | - Parag Mallick
- Nautilus Biotechnology, 201 Industrial Rd #310, San Carlos, CA, 94070, USA
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Miller BS, Bezinge L, Gliddon HD, Huang D, Dold G, Gray ER, Heaney J, Dobson PJ, Nastouli E, Morton JJL, McKendry RA. Spin-enhanced nanodiamond biosensing for ultrasensitive diagnostics. Nature 2020; 587:588-593. [PMID: 33239800 DOI: 10.1038/s41586-020-2917-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/16/2020] [Indexed: 01/06/2023]
Abstract
The quantum spin properties of nitrogen-vacancy defects in diamond enable diverse applications in quantum computing and communications1. However, fluorescent nanodiamonds also have attractive properties for in vitro biosensing, including brightness2, low cost3 and selective manipulation of their emission4. Nanoparticle-based biosensors are essential for the early detection of disease, but they often lack the required sensitivity. Here we investigate fluorescent nanodiamonds as an ultrasensitive label for in vitro diagnostics, using a microwave field to modulate emission intensity5 and frequency-domain analysis6 to separate the signal from background autofluorescence7, which typically limits sensitivity. Focusing on the widely used, low-cost lateral flow format as an exemplar, we achieve a detection limit of 8.2 × 10-19 molar for a biotin-avidin model, 105 times more sensitive than that obtained using gold nanoparticles. Single-copy detection of HIV-1 RNA can be achieved with the addition of a 10-minute isothermal amplification step, and is further demonstrated using a clinical plasma sample with an extraction step. This ultrasensitive quantum diagnostics platform is applicable to numerous diagnostic test formats and diseases, and has the potential to transform early diagnosis of disease for the benefit of patients and populations.
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Affiliation(s)
- Benjamin S Miller
- London Centre for Nanotechnology, University College London, London, UK. .,Division of Medicine, University College London, London, UK.
| | - Léonard Bezinge
- London Centre for Nanotechnology, University College London, London, UK
| | - Harriet D Gliddon
- London Centre for Nanotechnology, University College London, London, UK
| | - Da Huang
- London Centre for Nanotechnology, University College London, London, UK
| | - Gavin Dold
- London Centre for Nanotechnology, University College London, London, UK.,Department of Electronic and Electrical Engineering, University College London, London, UK
| | - Eleanor R Gray
- London Centre for Nanotechnology, University College London, London, UK
| | - Judith Heaney
- Advanced Pathogens Diagnostic Unit, University College London Hospitals, London, UK
| | | | - Eleni Nastouli
- Department of Virology, University College London Hospitals, London, UK
| | - John J L Morton
- London Centre for Nanotechnology, University College London, London, UK.,Department of Electronic and Electrical Engineering, University College London, London, UK
| | - Rachel A McKendry
- London Centre for Nanotechnology, University College London, London, UK. .,Division of Medicine, University College London, London, UK.
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Gabrys PA, Zornberg LZ, Macfarlane RJ. Programmable Atom Equivalents: Atomic Crystallization as a Framework for Synthesizing Nanoparticle Superlattices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1805424. [PMID: 30970182 DOI: 10.1002/smll.201805424] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Decades of research efforts into atomic crystallization phenomenon have led to a comprehensive understanding of the pathways through which atoms form different crystal structures. With the onset of nanotechnology, methods that use colloidal nanoparticles (NPs) as nanoscale "artificial atoms" to generate hierarchically ordered materials are being developed as an alternative strategy for materials synthesis. However, the assembly mechanisms of NP-based crystals are not always as well-understood as their atomic counterparts. The creation of a tunable nanoscale synthon whose assembly can be explained using the context of extensively examined atomic crystallization will therefore provide significant advancement in nanomaterials synthesis. DNA-grafted NPs have emerged as a strong candidate for such a "programmable atom equivalent" (PAE), because the predictable nature of DNA base-pairing allows for complex yet easily controlled assembly. This Review highlights the characteristics of these PAEs that enable controlled assembly behaviors analogous to atomic phenomena, which allows for rational material design well beyond what can be achieved with other crystallization techniques.
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Affiliation(s)
- Paul A Gabrys
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Leonardo Z Zornberg
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Robert J Macfarlane
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
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Yu H, Xu X, Liang P, Loh KY, Guntupalli B, Roncancio D, Xiao Y. A Broadly Applicable Assay for Rapidly and Accurately Quantifying DNA Surface Coverage on Diverse Particles. Bioconjug Chem 2017; 28:933-943. [PMID: 28156100 DOI: 10.1021/acs.bioconjchem.6b00660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
DNA-modified particles are used extensively for applications in sensing, material science, and molecular biology. The performance of such DNA-modified particles is greatly dependent on the degree of surface coverage, but existing methods for quantitation can only be employed for certain particle compositions and/or conjugation chemistries. We have developed a simple and broadly applicable exonuclease III (Exo III) digestion assay based on the cleavage of phosphodiester bonds-a universal feature of DNA-modified particles-to accurately quantify DNA probe surface coverage on diverse, commonly used particles of different compositions, conjugation chemistries, and sizes. Our assay utilizes particle-conjugated, fluorophore-labeled probes that incorporate two abasic sites; these probes are hybridized to a complementary DNA (cDNA) strand, and quantitation is achieved via cleavage and digestion of surface-bound probe DNA via Exo III's apurinic endonucleolytic and exonucleolytic activities. The presence of the two abasic sites in the probe greatly speeds up the enzymatic reaction without altering the packing density of the probes on the particles. Probe digestion releases a signal-generating fluorophore and liberates the intact cDNA strand to start a new cycle of hybridization and digestion, until all fluorophore tags have been released. Since the molar ratio of fluorophore to immobilized DNA is 1:1, DNA surface coverage can be determined accurately based on the complete release of fluorophores. Our method delivers accurate, rapid, and reproducible quantitation of thiolated DNA on the surface of gold nanoparticles, and also performs equally well with other conjugation chemistries, substrates, and particle sizes, and thus offers a broadly useful assay for quantitation of DNA surface coverage.
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Affiliation(s)
- Haixiang Yu
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | - Xiaowen Xu
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | - Pingping Liang
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | - Kang Yong Loh
- Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Bhargav Guntupalli
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | - Daniel Roncancio
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | - Yi Xiao
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
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Abstract
RNA interference (RNAi)-based gene regulation has recently emerged as a promising strategy to silence genes that drive disease progression. RNAi is typically mediated by small interfering ribonucleic acids (siRNAs), which, upon delivery into the cell cytoplasm, trigger degradation of complementary messenger RNA molecules to halt production of their encoded proteins. While RNAi has enormous clinical potential, its in vivo utility has been hindered because siRNAs are rapidly degraded by nucleases, cannot passively enter cells, and are quickly cleared from the bloodstream. To overcome these delivery barriers, siRNAs can be conjugated to nanoparticles (NPs), which increase their stability and circulation time to enable in vivo gene regulation. Here, we present methods to conjugate siRNA duplexes to NPs with gold surfaces. Further, we describe how to quantify the resultant amount of siRNA sense and antisense strands loaded onto the NPs using a fluorescence-based assay. This method focuses on the attachment of siRNAs to 13 nm gold NPs, but it is adaptable to other types of nucleic acids and nanoparticles as discussed throughout the protocol.
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Dharanivasan G, Mohammed Riyaz SU, Michael Immanuel Jesse D, Raja Muthuramalingam T, Rajendran G, Kathiravan K. DNA templated self-assembly of gold nanoparticle clusters in the colorimetric detection of plant viral DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe. RSC Adv 2016. [DOI: 10.1039/c5ra25559g] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The DNA templated self-assembly of gold nanoparticles clustered in different configurations (nn = 2–∞) was investigated in the colorimetric detection of ToLCNDV DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe.
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Affiliation(s)
- G. Dharanivasan
- Department of Biotechnology
- University of Madras
- Chennai 600 025
- India
| | | | | | | | - G. Rajendran
- Department of Biotechnology
- University of Madras
- Chennai 600 025
- India
| | - K. Kathiravan
- Department of Biotechnology
- University of Madras
- Chennai 600 025
- India
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8
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Wan Y, Wang P, Su Y, Wang L, Pan D, Aldalbahi A, Yang S, Zuo X. Nanoprobe-Initiated Enzymatic Polymerization for Highly Sensitive Electrochemical DNA Detection. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25618-25623. [PMID: 26524941 DOI: 10.1021/acsami.5b08817] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electrochemical DNA (E-DNA) sensors have been greatly developed and play an important role in early diagnosis of different diseases. To determine the extremely low abundance of DNA biomarkers in clinical samples, scientists are making unremitting efforts toward achieving highly sensitive and selective E-DNA sensors. Here, a novel E-DNA sensor was developed taking advantage of the signal amplification efficiency of nanoprobe-initiated enzymatic polymerization (NIEP). In the NIEP based E-DNA sensor, the capture probe DNA was thiolated at its 3'-terminal to be immobilized onto gold electrode, and the nanoprobe was fabricated by 5'-thiol-terminated signal probe DNA conjugated gold nanoparticles (AuNPs). Both of the probes could simultaneously hybridize with the target DNA to form a "sandwich" structure followed by the terminal deoxynucleotidyl transferase (TdT)-catalyzed elongation of the free 3'-terminal of DNA on the nanoprobe. During the DNA elongation, biotin labels were incorporated into the NIEP-generated long single-stranded DNA (ssDNA) tentacles, leading to specific binding of avidin modified horseradish peroxidase (Av-HRP). Since there are hundreds of DNA probes on the nanoprobe, one hybridization event would generate hundreds of long ssDNA tentacles, resulting in tens of thousands of HRP catalyzed reduction of hydrogen peroxide and sharply increasing electrochemical signals. By employing nanoprobe and TdT, it is demonstrated that the NIEP amplified E-DNA sensor has a detection limit of 10 fM and excellent differentiation ability for even single-base mismatch.
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Affiliation(s)
| | | | | | - Lihua Wang
- Division of Physical Biology and Bioimaging Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800, China
| | - Dun Pan
- Division of Physical Biology and Bioimaging Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800, China
| | - Ali Aldalbahi
- Chemistry Department, King Saud University , Riyadh 11451, Saudi Arabia
| | | | - Xiaolei Zuo
- Division of Physical Biology and Bioimaging Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800, China
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Li Y, Yan L, Liu Y, Qian K, Liu B, Yang P, Liu B. High-efficiency nano/micro-reactors for protein analysis. RSC Adv 2015. [DOI: 10.1039/c4ra12333f] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This article reviews the recent advances regarding the development of nanomaterial-based nanoreactors and microfluidic droplet reactors and their applications in protein analysis.
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Affiliation(s)
- Yixin Li
- Department of Chemistry and Institutes of Biomedical Sciences
- Fudan University
- Shanghai 200433
- China
| | - Ling Yan
- Department of Chemistry and Institutes of Biomedical Sciences
- Fudan University
- Shanghai 200433
- China
| | - Yun Liu
- Department of Chemistry and Institutes of Biomedical Sciences
- Fudan University
- Shanghai 200433
- China
| | - Kun Qian
- Center for Bio-Nano-Chips and Diagnostics in Translational Medicine
- School of Biomedical Engineering and Med-X Research Institute
- Shanghai Jiao Tong University
- Shanghai
- China
| | - Bin Liu
- Center for Bio-Nano-Chips and Diagnostics in Translational Medicine
- School of Biomedical Engineering and Med-X Research Institute
- Shanghai Jiao Tong University
- Shanghai
- China
| | - Pengyuan Yang
- Department of Chemistry and Institutes of Biomedical Sciences
- Fudan University
- Shanghai 200433
- China
| | - Baohong Liu
- Department of Chemistry and Institutes of Biomedical Sciences
- Fudan University
- Shanghai 200433
- China
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10
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Bu D, Zhuang H. A real-time immuno-PCR assay for the flame retardant tris(2,3-dibromopropyl) isocyanurate using a probe DNA conjugated to gold nanoparticles. Mikrochim Acta 2014. [DOI: 10.1007/s00604-014-1416-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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11
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Mu Q, Jiang G, Chen L, Zhou H, Fourches D, Tropsha A, Yan B. Chemical basis of interactions between engineered nanoparticles and biological systems. Chem Rev 2014; 114:7740-81. [PMID: 24927254 PMCID: PMC4578874 DOI: 10.1021/cr400295a] [Citation(s) in RCA: 358] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Qingxin Mu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, China, 250100
- Present address: Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, Kansas, 66047
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Lingxin Chen
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | - Hongyu Zhou
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, China, 250100
- Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, 30322, U.S.A
| | | | - Alexander Tropsha
- Laboratory for Molecular Modeling, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Bing Yan
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, China, 250100
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Jiwaji M, Sandison ME, Reboud J, Stevenson R, Daly R, Barkess G, Faulds K, Kolch W, Graham D, Girolami MA, Cooper JM, Pitt AR. Quantification of functionalised gold nanoparticle-targeted knockdown of gene expression in HeLa cells. PLoS One 2014; 9:e99458. [PMID: 24926959 PMCID: PMC4057226 DOI: 10.1371/journal.pone.0099458] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 05/13/2014] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Gene therapy continues to grow as an important area of research, primarily because of its potential in the treatment of disease. One significant area where there is a need for better understanding is in improving the efficiency of oligonucleotide delivery to the cell and indeed, following delivery, the characterization of the effects on the cell. METHODS In this report, we compare different transfection reagents as delivery vehicles for gold nanoparticles functionalized with DNA oligonucleotides, and quantify their relative transfection efficiencies. The inhibitory properties of small interfering RNA (siRNA), single-stranded RNA (ssRNA) and single-stranded DNA (ssDNA) sequences targeted to human metallothionein hMT-IIa are also quantified in HeLa cells. Techniques used in this study include fluorescence and confocal microscopy, qPCR and Western analysis. FINDINGS We show that the use of transfection reagents does significantly increase nanoparticle transfection efficiencies. Furthermore, siRNA, ssRNA and ssDNA sequences all have comparable inhibitory properties to ssDNA sequences immobilized onto gold nanoparticles. We also show that functionalized gold nanoparticles can co-localize with autophagosomes and illustrate other factors that can affect data collection and interpretation when performing studies with functionalized nanoparticles. CONCLUSIONS The desired outcome for biological knockdown studies is the efficient reduction of a specific target; which we demonstrate by using ssDNA inhibitory sequences targeted to human metallothionein IIa gene transcripts that result in the knockdown of both the mRNA transcript and the target protein.
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Affiliation(s)
- Meesbah Jiwaji
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- School of Life and Health Science, Aston University, Birmingham, United Kingdom
| | - Mairi E. Sandison
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Julien Reboud
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Ross Stevenson
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Rónán Daly
- School of Computing Science, University of Glasgow, Glasgow, United Kingdom
| | - Gráinne Barkess
- Institute of Cancer Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Karen Faulds
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Walter Kolch
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Systems Biology Ireland and the Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Duncan Graham
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Mark A. Girolami
- School of Computing Science, University of Glasgow, Glasgow, United Kingdom
- Department of Statistical Science, University College London, London, United Kingdom
| | - Jonathan M. Cooper
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Andrew R. Pitt
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- School of Life and Health Science, Aston University, Birmingham, United Kingdom
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Paliwoda RE, Li F, Reid MS, Lin Y, Le XC. Sequential Strand Displacement Beacon for Detection of DNA Coverage on Functionalized Gold Nanoparticles. Anal Chem 2014; 86:6138-43. [DOI: 10.1021/ac501341t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Rebecca E. Paliwoda
- Department of Chemistry, and ‡Department of Laboratory Medicine
and Pathology, Division of Analytical and Environmental
Toxicology, University of Alberta, Edmonton, Alberta T6G2G3, Canada
| | - Feng Li
- Department of Chemistry, and ‡Department of Laboratory Medicine
and Pathology, Division of Analytical and Environmental
Toxicology, University of Alberta, Edmonton, Alberta T6G2G3, Canada
| | - Michael S. Reid
- Department of Chemistry, and ‡Department of Laboratory Medicine
and Pathology, Division of Analytical and Environmental
Toxicology, University of Alberta, Edmonton, Alberta T6G2G3, Canada
| | - Yanwen Lin
- Department of Chemistry, and ‡Department of Laboratory Medicine
and Pathology, Division of Analytical and Environmental
Toxicology, University of Alberta, Edmonton, Alberta T6G2G3, Canada
| | - X. Chris Le
- Department of Chemistry, and ‡Department of Laboratory Medicine
and Pathology, Division of Analytical and Environmental
Toxicology, University of Alberta, Edmonton, Alberta T6G2G3, Canada
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Thavanathan J, Huang NM, Thong KL. Colorimetric detection of DNA hybridization based on a dual platform of gold nanoparticles and graphene oxide. Biosens Bioelectron 2014; 55:91-8. [DOI: 10.1016/j.bios.2013.11.072] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/24/2013] [Accepted: 11/28/2013] [Indexed: 12/19/2022]
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Takei F, Nakatani K. The Chemistry of Polymerase Chain Reaction^|^mdash;Development of the PCR Method Using New Modified Primers^|^mdash;. J SYN ORG CHEM JPN 2014. [DOI: 10.5059/yukigoseikyokaishi.72.370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Ahmadpour-Yazdi H, Hormozi-Nezhad M, Abadi A, Sanati MH, Kazemi B. Colorimetric Assay for Exon 7 SMN1/SMN2 Single Nucleotide Polymorphism Using Gold Nanoprobes. BIOIMPACTS : BI 2013; 3:185-94. [PMID: 24455482 DOI: 10.5681/bi.2013.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 11/29/2013] [Accepted: 12/15/2013] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Proximal spinal muscular atrophy (SMA) is one of the most significant neurodegenerative diseases amongst the autosomal-recessive genetic disorders which is caused by the absence of protein survival of motor neuron (SMN). A critical nucleotide difference in SMN2 compared to SMN1 gene leads to an inefficient protein. Hence, homozygous lack of SMN1 provides a progressive disease. Due to the high prevalence, up to now, several molecular diagnostic methods have been used which most of them are lengthy, expensive, and laborious. METHODS In the present study, we exploited a gold nanoprobe-based method for semi-quantitative SMN1 gene dosage analysis compared to SMN2. The assay was done under hybridization process between Au nanoprobes and different ratios of SMN1/SMN2 amplicons. RESULTS UV-vis spectra indicated that after the salt addition, nanoprobes aggregated gradually and their peak shifted to longer wavelengths except in the stable target-nanoprobes hybridization. The results revealed that the homozygous genotype of SMN2 gene is distinguished from the heterozygous genotypes of SMN genes by the naked eye, whereas different ratio of heterozygous genotypes (SMN1/SMN2) are differentiated better from each other using peak analysis ratios. CONCLUSION The presented strategy is an alternative simple method for discrimination of homozygous deletion of SMN1 in less than 30 min. However, further evaluation of the assay using clinical samples is recommended prior to real-world use.
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Affiliation(s)
- Hossein Ahmadpour-Yazdi
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Hormozi-Nezhad
- Department of Chemistry, Sharif University of Technology, Tehran, Iran ; Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran
| | - Ali Abadi
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
| | - Mohammad Hossein Sanati
- Department of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e- Pajoohesh, 15th Km, Tehran -Karaj Highway, Tehran, Iran
| | - Bahram Kazemi
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Department of Biotechnology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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17
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Deng B, Sun Z, Jason W, Yang P. Increased BCAR1 predicts poor outcomes of non-small cell lung cancer in multiple-center patients. Ann Surg Oncol 2013; 20 Suppl 3:S701-8. [PMID: 23904007 DOI: 10.1245/s10434-013-3184-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Indexed: 12/14/2022]
Abstract
OBJECTIVE This study was designed to determine the prognostic value of BCAR1 expression and its associations with clinical-demographical characteristics in multiple centers of non-small cell lung cancer (NSCLC) patients. METHODS Gene expression microarray (mRNA) of 77 adenocarcinomas from Mayo Clinic, RNA-sequencing of 508 NSCLC from The Cancer Genome Atlas (TCGA), and immunohistochemistry stain of BCAR1-protein expression in 150 cases from Daping Hospital were included in the study. The association of mRNA or protein expression with patient clinical characteristics and overall survival was assessed in each dataset. We also predicted microRNAs (miRNA) that target BCAR1 using bioinformatics prediction tools and evaluated miRNA expression patterns with BCAR1 expression in miRNA-sequencing data of 74 lung cancer cases from TCGA dataset. RESULTS In the Mayo Clinic dataset, a higher BCAR1-mRNA level correlated significantly with more advanced tumor-stage and lymphatic metastasis. Similar changes were observed in the TCGA RNA-seq dataset. Additionally, higher BCAR1-mRNA levels predicted poorer survival in adenocarcinoma and squamous carcinoma from the TCGA dataset. The protein levels in the adenocarcinoma cases with lymphatic metastasis were significantly higher than of those without metastasis. Tumor tissues demonstrated remarkably higher levels of protein compared with matched normal tissues although there was no significant difference in BCAR1-mRNA expression between tumor and matched normal tissues was detected. In miRNAs that were downregulated in the tumors, Let-7f-2 and miR-22 differed the most (P < 0.001 and P = 0.007, respectively). CONCLUSIONS We confirmed that increased BCAR1 expression predicts poorer prognosis in NSCLC. We postulate that mRNA-protein decoupling of BCAR1 may be a result of reduced inhibition of specific miRNAs in tumor tissues, which warrants further study.
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Affiliation(s)
- Bo Deng
- Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, College of Medicine, Rochester, MN, USA
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Guerrini L, Barrett L, Dougan JA, Faulds K, Graham D. Improving the understanding of oligonucleotide-nanoparticle conjugates using DNA-binding fluorophores. NANOSCALE 2013; 5:4166-4170. [PMID: 23598624 DOI: 10.1039/c3nr01197f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel fluorescent-based method for characterisation of oligonucleotide-nanoparticle conjugates (ONPCs) is reported. We exploit the ability of the double-stranded DNA-binding dye, SYBR Green I, to develop a powerful analytical tool to investigate the melting properties and hybridisation behavior of ONPCs as well as their corresponding DNA-mediated assemblies.
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Affiliation(s)
- Luca Guerrini
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1YL, UK.
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Montenegro JM, Grazu V, Sukhanova A, Agarwal S, de la Fuente JM, Nabiev I, Greiner A, Parak WJ. Controlled antibody/(bio-) conjugation of inorganic nanoparticles for targeted delivery. Adv Drug Deliv Rev 2013; 65:677-88. [PMID: 23280372 DOI: 10.1016/j.addr.2012.12.003] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 12/05/2012] [Accepted: 12/21/2012] [Indexed: 12/29/2022]
Abstract
Arguably targeting is one of the biggest problems for controlled drug delivery. In the case that drugs can be directed with high efficiency to the target tissue, side effects of medication are drastically reduced. Colloidal inorganic nanoparticles (NPs) have been proposed and described in the last 10years as new platforms for in vivo delivery. However, though NPs can introduce plentiful functional properties (such as controlled destruction of tissue by local heating or local generation of free radicals), targeting remains an issue of intense research efforts. While passive targeting of NPs has been reported (the so-called enhanced permeation and retention, EPR effect), still improved active targeting would be highly desirable. One classical approach for active targeting is mediated by molecular recognition via capture molecules, i.e. antibodies (Abs) specific for the target. In order to apply this strategy for NPs, they need to be conjugated with Abs against specific biomarkers. Though many approaches have been reported in this direction, the controlled bioconjugation of NPs is still a challenge. In this article the strategies of controlled bioconjugation of NPs will be reviewed giving particular emphasis to the following questions: 1) how can the number of capture molecules per NP be precisely adjusted, and 2) how can the Abs be attached to NP surfaces in an oriented way. Solution of both questions is a cornerstone in controlled targeting of the inorganic NPs bioconjugates.
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Montiel D, Yates EV, Sun L, Sampias MM, Malona J, Sorensen EJ, Yang H. Ligand synthesis and passivation for silver and large gold nanoparticles for single-particle-based sensing and spectroscopy. Methods Mol Biol 2013; 1025:237-50. [PMID: 23918342 PMCID: PMC7075696 DOI: 10.1007/978-1-62703-462-3_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Silver and large gold nanoparticles are more efficient scatterers than smaller particles, which can be advantageous for a variety of single-particle-based sensing and spectroscopic applications. The increased susceptibility to surface oxidation and the larger surface area of these particles, however, present challenges to colloid stability and controllable bio-conjugation strategies. In this chapter, ligand syntheses and particle passivation procedures for yielding stable and bio-conjugatable colloids of silver and large gold nanoparticles are described.
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Kurkina T, Balasubramanian K. Towards in vitro molecular diagnostics using nanostructures. Cell Mol Life Sci 2012; 69:373-88. [PMID: 22009454 PMCID: PMC11115035 DOI: 10.1007/s00018-011-0855-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 09/29/2011] [Accepted: 09/29/2011] [Indexed: 10/16/2022]
Abstract
Nanostructures appear to be promising for a number of applications in molecular diagnostics, mainly due to the increased surface-to-volume ratio they can offer, the very low limit of detection achievable, and the possibility to fabricate point-of-care diagnostic devices. In this paper, we review examples of the use of nanostructures as diagnostic tools that bring in marked improvements over prevalent classical assays. The focus is laid on the various sensing paradigms that possess the potential or have demonstrated the capability to replace or augment current analytical strategies. We start with a brief introduction of the various types of nanostructures and their physical properties that determine the transduction principle. This is followed by a concise collection of various functionalization protocols used to immobilize biomolecules on the nanostructure surface. The sensing paradigms are discussed in two contexts: the nanostructure acting as a label for detection, or the nanostructure acting as a support upon which the molecular recognition events take place. In order to be successful in the field of molecular diagnostics, it is important that the nanoanalytical tools be evaluated in the appropriate biological environment. The final section of the review compiles such examples, where the nanostructure-based diagnostic tools have been tested on realistic samples such as serum, demonstrating their analytical power even in the presence of complex matrix effects. The ability of nanodiagnostic tools to detect ultralow concentrations of one or more analytes coupled with portability and the use of low sample volumes is expected to have a broad impact in the field of molecular diagnostics.
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Affiliation(s)
- Tetiana Kurkina
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Kannan Balasubramanian
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
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22
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Potůčková L, Franko F, Bambousková M, Dráber P. Rapid and sensitive detection of cytokines using functionalized gold nanoparticle-based immuno-PCR, comparison with immuno-PCR and ELISA. J Immunol Methods 2011; 371:38-47. [PMID: 21704628 DOI: 10.1016/j.jim.2011.06.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 06/09/2011] [Accepted: 06/13/2011] [Indexed: 02/05/2023]
Abstract
Reliable and simple methods are required for detection of low concentrations of cytokines and some other proteins in complex biological fluids. This is especially important when monitoring the immune responses under various physiological and pathophysiological conditions in vivo or following production of these compounds in in vitro systems. Cytokines and other immunologically active molecules are being predominantly detected by enzyme-linked immunosorbent assays (ELISA) and newly also by immuno-polymerase chain reactions (iPCR). New simplified variants of iPCR have recently been described where antibodies are connected with multiple DNA templates through gold nanoparticles (Au-NPs) to form a new class of detection reagents. In this study we compared functionalized Au-NP-based iPCR (Nano-iPCR) with standard ELISA and iPCR for the detection of interleukin (IL)-3 and stem cell factor (SCF). The same immunoreagents (IL-3- and SCF-specific polyclonal antibodies and their biotinylated forms) were used throughout the assays. The obtained data indicate that both Nano-iPCR and iPCR are superior in sensitivity and detection range than ELISA. Furthermore, Nano-iPCR is easier to perform than the other two methods. Nano-iPCR was used for monitoring changes in concentration of free SCF during growth of mast cells in SCF-conditioned media. The results show that growing cultures gradually reduce the amount of SCF in supernatant to 25% after 5 days. The combined data indicate that Nano-iPCR assays may be preferable for rapid detection of low concentrations of cytokines in complex biological fluids.
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Affiliation(s)
- Lucie Potůčková
- Laboratory of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ-14220 Prague 4, Czech Republic
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Ding YZ, Liu YS, Zhou JH, Chen HT, Zhang J, Ma LN, Wei G. A highly sensitive detection for foot-and-mouth disease virus by gold nanopariticle improved immuno-PCR. Virol J 2011; 8:148. [PMID: 21453461 PMCID: PMC3080827 DOI: 10.1186/1743-422x-8-148] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 03/31/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Foot-and-mouth disease (FMD) is one of the most contagious of all artiodactyl animal diseases, and its infection has an obvious ability to spread over long distances and to contribute to epidemics in FMD-free areas. A highly sensitive and specific method is required to detect FMDV. In this study, we evaluated the usefulness of a bio-barcode assay (BCA) technique for detecting clinical samples of FMDV. METHODS Highly sensitive gold nanopariticle (GNP) improved immuno -PCR (GNP-IPCR) which derived from the bio-barcode assay (BCA) was designed for the detection of FMDV. The target viral particles were captured by a polyclonal antibody coated on ELISA microplate, followed by adding GNP which was dually modified with oligonucleotides and a FMDV specific monoclonal antibody (MAb) 1D11 to form a sandwiched immune complex. After the formation of immuno-complex, the signal DNA was released by heating, and consequently characterized by PCR and real time PCR. RESULTS The detection limit of GNP-PCR could reach to 10 fg/ml purified FMDV particles, and the assay can detect clinical samples of FMDV with highly sensitivity, while detect limit of conventional ELISA is 100 ng/ml in this study. CONCLUSION GNP-IPCR may provide a highly sensitive method for the detection of FMDV.
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Affiliation(s)
- Yao-zhong Ding
- Chinese Academy of Agricultural Sciences, Lanzhou, Gansu,China
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Zhang D, Ansar SM. Ratiometric Surface Enhanced Raman Quantification of Ligand Adsorption onto a Gold Nanoparticle. Anal Chem 2010; 82:5910-4. [DOI: 10.1021/ac1010124] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dongmao Zhang
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762
| | - Siyam M. Ansar
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762
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Hiep HM, Kerman K, Endo T, Saito M, Tamiya E. Nanostructured biochip for label-free and real-time optical detection of polymerase chain reaction. Anal Chim Acta 2010; 661:111-6. [DOI: 10.1016/j.aca.2009.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 12/02/2009] [Accepted: 12/08/2009] [Indexed: 10/20/2022]
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Chen L, Wei H, Guo Y, Cui Z, Zhang Z, Zhang XE. Gold nanoparticle enhanced immuno-PCR for ultrasensitive detection of Hantaan virus nucleocapsid protein. J Immunol Methods 2009; 346:64-70. [DOI: 10.1016/j.jim.2009.05.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 05/04/2009] [Accepted: 05/20/2009] [Indexed: 10/20/2022]
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Sz-Hau Chen, Kun-I Lin, Chuan-Yi Tang, Sheng-Lung Peng, Yao-Chen Chuang, Yi-Rou Lin, Jui-Ping Wang, Chih-Sheng Lin. Optical Detection of Human Papillomavirus Type 16 and Type 18 by Sequence Sandwich Hybridization With Oligonucleotide-Functionalized Au Nanoparticles. IEEE Trans Nanobioscience 2009; 8:120-31. [DOI: 10.1109/tnb.2008.2011733] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pal S, Kim MJ, Song JM. Quantitation of surface coverage of oligonucleotides bound to chip surfaces: a fluorescence-based approach using alkaline phosphatase digestion. LAB ON A CHIP 2008; 8:1332-1341. [PMID: 18651076 DOI: 10.1039/b804066d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Silanized chip surfaces provide a reliable substrate for immobilization of oligonucleotides. The ability for rapid and sensitive detection of oligonucleotide surface coverage on these chips is crucial for their wide and effective applications in biotechnology. In this paper, two different silanization procedures were used to covalently bind fluorescent-labeled single-stranded DNA onto silicon dioxide or nitride chip surfaces. Effects of surface functionalization techniques for different surfaces, and immobilization conditions, including buffers and solution ionic strength, on surface probe coverage were investigated, quantifying the endpoint probe density by fluorescent measurement upon digestion with alkaline phosphatase (ALP). Digestion of surface-immobilized oligonuleotides with ALP released the fluorophore-tagged probe fragments back into the solution. The detection of DNA was accomplished by laser-induced fluorescence detection of the solution containing those cleaved fragments. The probe surface density on gold thin film, determined by ALP-digestion, was found to coincide well with that measured using the conventional alkanethiol-based fluorescence-displacement technique for the same system. The developed method has important implications for evaluating the performance of different oligonucleotide immobilization strategies. Also, it has the potential to serve as a sample-thrifty, time saving, and therefore routine tool to realize more realistic, practical quantification of the surface coverage of oligonucleotides immobilized on any solid surfaces.
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Affiliation(s)
- Sukdeb Pal
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul, 151-742, South Korea
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29
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Kim EY, Stanton J, Korber BTM, Krebs K, Bogdan D, Kunstman K, Wu S, Phair JP, Mirkin CA, Wolinsky SM. Detection of HIV-1 p24 Gag in plasma by a nanoparticle-based bio-barcode-amplification method. Nanomedicine (Lond) 2008; 3:293-303. [PMID: 18510425 PMCID: PMC2821699 DOI: 10.2217/17435889.3.3.293] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Detection of HIV-1 in patients is limited by the sensitivity and selectivity of available tests. The nanotechnology-based bio-barcode-amplification method offers an innovative approach to detect specific HIV-1 antigens from diverse HIV-1 subtypes. We evaluated the efficacy of this protein-detection method in detecting HIV-1 in men enrolled in the Chicago component of the Multicenter AIDS Cohort Study (MACS). METHODS The method relies on magnetic microparticles with antibodies that specifically bind the HIV-1 p24 Gag protein and nanoparticles that are encoded with DNA and antibodies that can sandwich the target protein captured by the microparticle-bound antibodies. The aggregate sandwich structures are magnetically separated from solution, and treated to remove the conjugated barcode DNA. The DNA barcodes (hundreds per target) were identified by a nanoparticle-based detection method that does not rely on PCR. RESULTS Of 112 plasma samples from HIV-1-infected subjects, 111 were positive for HIV-1 p24 Gag protein (range: 0.11-71.5 ng/ml of plasma) by the bio-barcode-amplification method. HIV-1 p24 Gag protein was detected in only 23 out of 112 men by the conventional ELISA. A total of 34 uninfected subjects were negative by both tests. Thus, the specificity of the bio-barcode-amplification method was 100% and the sensitivity 99%. The bio-barcode-amplification method detected HIV-1 p24 Gag protein in plasma from all study subjects with less than 200 CD4(+) T cells/microl of plasma (100%) and 19 out of 20 (95%) HIV-1-infected men who had less than 50 copies/ml of plasma of HIV-1 RNA. In a separate group of 60 diverse international isolates, representative of clades A, B, C and D and circulating recombinant forms CRF01_AE and CRF02_AG, the bio-barcode-amplification method identified the presence of virus correctly. CONCLUSIONS The bio-barcode-amplification method was superior to the conventional ELISA assay for the detection of HIV-1 p24 Gag protein in plasma with a breadth of coverage for diverse HIV-1 subtypes. Because the bio-barcode-amplification method does not require enzymatic amplification, this method could be translated into a robust point-of-care test.
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Affiliation(s)
- Eun-Young Kim
- Division of Infectious Diseases, The Feinberg School of Medicine, Northwestern University, 676 North St. Clair, Chicago, IL 60611, USA
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