Preparation of Quantum Dot−Biotin Conjugates and Their Use in Immunochromatography Assays

Lingerfelt, Brian M.; Mattoussi, Hedi; Goldman, Ellen R.; Mauro, J. Matthew; Anderson, George P.

doi:10.1021/ac034139e

Cited by 120 publications

(69 citation statements)

References 33 publications

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“…[21a, 75,272] CdSe core /ZnS shell NPs were functionalized with avidin and these were used as fluorescent labels for biotinylated antibodies. Fluoroimmunoassays utilizing these antibody-conjugated NPs were successfully used in the detection of protein toxins (staphylococcal enterotoxin B and cholera toxin).…”

Section: Methodsmentioning

confidence: 99%

Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and Applications

2004

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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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Section: Methodsmentioning

confidence: 99%

Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and Applications

2004

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“…For example, luminescent semiconductor quantum dots are a promising alternative to organic dyes for fluorescence applications since they are more stable against photobleaching and have narrow and size-tunable multicolour emission as well as the functional advantages [21,22]. Some of the most exciting applications involve new generation of optoelectronic [23][24][25][26] and photovoltaic devices [27] and exploratory biotechnology research as ultra-sensitive biological fluorescent tags [22,[28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Adsorption and photoreactivity of CdSe nanoparticles at liquid|liquid interfaces

Fermı́n

Abid

et al. 2005

Journal of Electroanalytical Chemistry

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The voltage induced assembly and photoreactivity of cadmium selenide (CdSe) nanoparticles protected by mercaptosuccinic acid are studied at the polarisable interface between water and 1,2-dichloroethane electrolyte solutions. Cyclic voltammograms and admittance measurements show an increase of the interface excess charge associated with the adsorption of CdSe nanoparticles as the Galvani potential difference is tuned to negative values with respect to the potential in the organic phase. Within the potential range where the nanoparticles are adsorbed, band-gap illumination leads to heterogeneous electron transfer from CdSe nanoparticles to electron acceptors located in the organic phase. The interfacial Galvani potential difference plays an important role in these phenomena, as it affects the interfacial density of the nanoparticles, as well as the driving force for the electron transfer. The photocurrent efficiency also strongly depends on the formal redox potential of the electron acceptor, indicating that the heterogeneous photoreaction is kinetically controlled. The interfacial electron transfer occurs via depopulation of the deep trap states in the band gap. Analysis of the photocurrent transient responses reveals that the magnitude of the instantaneous photocurrent upon illumination is determined by the kinetics of heterogeneous electron transfer, while photogenerated holes are swiftly captured by species present in the aqueous phase. The photocurrent decay upon constant illumination is associated with the diffusion of the acceptor to the interfacial region. From the phenomenological point of view, the photoelectrochemical behaviour of CdSe nanoparticles can be compared to a self-assembled ultrathin p-type semiconductor photoelectrode.

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“…For example, biotin-labeled GSH-CdTe QDs could be prepared with preactivated N-hydroxysuccinimidobiotin (NHS-biotin) through direct conjugation to the amine group. [17] After removing the excess NHS-biotin with an ultracentrifuge filter (MWCO 10 000 g mol -1…”

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confidence: 99%

Synthesis and Cell‐Imaging Applications of Glutathione‐Capped CdTe Quantum Dots

2007

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Quantum dots (QDs) are of great interest to biological applications such as fluorescent biosensors and biolabels. Our study describes a synthesis of glutathione-capped CdTe QDs in aqueous solution that is cost-efficient and convenient compared to the conventional organometallic approaches. The fluorescence of the as-prepared glutathione-capped CdTe QDs was tunable from 500 to 650 nm. Without any postpreparation treatment, the glutathione-capped CdTe QDs achieved quantum yields (QYs) as high as 45 %, comparable to, or even better than, QDs derived from organometallic routes. With an overall size as small as 4 nm, they could gain access to cellular targets and stain fine features such as the cell nucleolus. These QDs were successfully conjugated with biotin for immunostaining and with F3 peptide for delivery to live cells, demonstrating their potentially broad application as biolabels.Fluorescent semiconductor nanoparticles or QDs have been extensively investigated in the past decade, and have been widely used as biolabels in imaging and biodetection.[1] Fluorescence imaging can greatly benefit from the use of QDs, which show brighter fluorescence, less photobleaching, and multiple colors with a single excitation. For biolabeling applications, QDs are commonly capped with trioctylphosphine oxide (TOPO) through organometallic synthesis, followed by phospholipid, [2] silica, [3] or polymer [4] coating to impart watersolubility and biocompatibility. With the multilayer coating, the final size of the QD biolabels would typically be 12-20 nm, which might be too bulky to gain access to cells for in vitro and in vivo imaging. In addition, the large dimensions would dramatically lower the labeling efficiency on specific target sites within the cells. Compared to conventionally used organic dyes, the size of QDs presented a major drawback as it limited the range of applications in biolabeling. To overcome this obstacle, water-soluble QDs with only one layer of capping ligand on the surface have been developed by ligand exchange with thiols [5] or phosphine [6] on TOPO-capped QDs.Both the ligand-addition and ligand-exchange methods were complicated, and even the high-quality QDs derived from organometallic methods have exhibited reductions in QY from 65-85 % in the organic phase to 35-50 % in aqueous solution.[7]Alternatively, thiol-capped QDs could be prepared directly in aqueous solution with thiols as stabilizers, but low QYs of 1-10 % were typically obtained.[8] Although their QYs could be significantly improved by a variety of after-treatments, such as photochemical etching, [8] size-selective precipitation, [9] and long-term illumination, [10] these QDs have a tendency to agglomerate during such treatments. Glutathione is a thiol-containing oligopeptide found in most organisms, and it plays an important role in the detoxification of heavy metals in plant cells. The physiological mechanism of detoxification involves the binding of heavy-metal nanoclusters by glutathione and the formation of a phytochelatin shell, cat...

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Preparation of Quantum Dot−Biotin Conjugates and Their Use in Immunochromatography Assays

Cited by 120 publications

References 33 publications

Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and Applications

Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and Applications

Adsorption and photoreactivity of CdSe nanoparticles at liquid|liquid interfaces

Synthesis and Cell‐Imaging Applications of Glutathione‐Capped CdTe Quantum Dots

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