Luminescent nanobeads: attachment of surface reactive Eu(iii) complexes to gold nanoparticles

Lewis, David J.; Day, Thomas M.; Macpherson, Julie V.; Pikramenou, Zoe

doi:10.1039/b518091k

Cited by 128 publications

(89 citation statements)

References 29 publications

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“…The interaction of pHLIP with AuNP is expected to take place via the disulfide linkage of the peptide in the C-terminus area. This is envisaged to be the strongest affinity site for gold (9,27) and any electrostatic interaction is excluded due to the negative charge on both nanoparticles and peptide (32). Subsequently, a solution of EuL was titrated in and led to a further 4-nm shift in the SPR band confirming the binding of EuL to the peptide-modified nanoparticles via the dithiol anchor points.…”

Section: Preparation and Characterization Of Phlip•eul•au Nanoparticlesmentioning

confidence: 99%

“…The advantage of the EuL complex is that it is neutral, with good stability (29), and does not interact with peptides on the nanoparticle as a free ion probe would (26). The "long legs" were chosen to avoid quenching of the europium luminescent signal from the gold resonance as previously observed (27). The europium complex was prepared following previously established procedures (30).…”

Section: Preparation and Characterization Of Phlip•eul•au Nanoparticlesmentioning

confidence: 99%

“…We have chosen to coat the inert gold nanoparticles with luminescent lanthanide probes as these are ideal optical probes for imaging in cells due to their distinctive emission profiles in the visible and near infrared regions of the spectrum, large Stokes shifts, and long luminescent lifetimes (23)(24)(25). Furthermore, gold nanoparticles can be functionalized with different peptides (9,26) and we have previously demonstrated that gold nanoparticles can be used as scaffolds for lanthanide complexes (27) and studied their uptake into cells (28) using transfection agents. Our approach involves a method of cocoating of the gold nanoparticles with the pHLIP peptide and a luminescent lanthanide complex, EuL, to achieve the delivery of a multiprobe, pHLIP•EuL•Au (Fig.…”

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confidence: 99%

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pH-controlled delivery of luminescent europium coated nanoparticles into platelets

Davies

Lewis²,

Watson

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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Water soluble, luminescent gold nanoparticles are delivered into human platelets via a rapid, pH-controlled mechanism using a pH low insertion peptide, pHLIP. The approach introduces cocoating of gold nanoparticles with a europium luminescent complex, EuL and the pHLIP peptide to give pHLIP•EuL•Au. The 13-nm diameter gold nanoparticles act as a scaffold for the attachment of both the luminescent probe and the peptide to target delivery. Their size allows delivery of approximately 640 lanthanide probes per nanoparticle to be internalized in human platelets, which are not susceptible to transfection or microinjection. The internalization of pHLIP•EuL•Au in platelets, which takes just minutes, was studied with a variety of imaging modalities including luminescence, confocal reflection, and transmission electron microscopy. The results show that pHLIP•EuL•Au only enters the platelets in low pH conditions, pH 6.5, mediated by the pHLIP translocation across the membrane, and not at pH 7.4. Luminescence microscopy images of the treated platelets show clearly the red luminescence signal from the europium probe and confocal reflection microscopy confirms the presence of the gold particles. Furthermore, transmission electron microscopy gives a detailed insight of the internalization and spatial localization of the gold nanoparticles in the platelets. Thus, we demonstrate the potential of the design to translocate multimodal nanoparticle probes into cells in a pH dependent manner.imaging | lanthanides | multimodal probes | pH low insertion peptide

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Section: Preparation and Characterization Of Phlip•eul•au Nanoparticlesmentioning

confidence: 99%

Section: Preparation and Characterization Of Phlip•eul•au Nanoparticlesmentioning

confidence: 99%

mentioning

confidence: 99%

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pH-controlled delivery of luminescent europium coated nanoparticles into platelets

Davies

Lewis²,

Watson

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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“…A chiral rhodiumdiphosphine complex anchored on gold nanoparticles has been successfully employed for asymmetric catalysis, leading to a full conversion and 93% yield in terms of enantiomeric excess, comparable to the free catalyst, in the hydrogenation of methyl a-acetamidocinnamate. 73 Similarly, a titanium(IV) bisnaphtol isopropoxide complex ( Figure 25) has been employed by Marubayashi et al 74 as an AuNP modifier, exhibiting a very high activity in the asymmetric alkylation of benzaldehyde, with enantiomeric excess superior to 80%. This catalyst has also the advantage of being easier to recuperate and purify.…”

Section: Assembling Coordination Compounds At Gold Nanoparticles Surfacementioning

confidence: 99%

The coordination chemistry at gold nanoparticles

Toma¹,

Zamarion²,

Toma³

et al. 2010

J. Braz. Chem. Soc.

117

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Nas nanopartículas de ouro, as propriedades químicas e físicas são ditadas principalmente pelos átomos da superfície, os quais podem interagir com espécies doadoras-aceitadoras, ou ligantes, da mesma forma que os complexos metálicos correspondentes. Além disso, os elétrons podem entrar em ressonância com a luz incidente dando origem aos plasmons de superfície, que levam à intensificação do campo elétrico local e ao efeito SERS, proporcionando uma ampla variedade de aplicações na química, biologia e nanotecnologia. Ligantes de ponte, multifuncionais, podem ser usados para intermediar a ligação de íons metálicos aos átomos de ouro da superfície. Essa estratégia permite controlar a estabilização em solução através das cargas dos complexos metálicos, acrescentando, ao mesmo tempo, novas características químicas e maior funcionalidade às nanopartículas modificadas. Dessa forma, uma nova química de coordenação pode ser vislumbrada, combinando nanopartículas metálicas, como as de ouro, e complexos, à luz da química supramolecular e dos efeitos de ressonância plasmônica de superfície.In gold nanoparticles the surface metal atoms play a major role, determining their chemical and physical properties by interacting with donor-acceptor species or ligands in a similar way as the related metal complexes. In addition, coherent oscillations of the metal electrons in resonance with the frequency of the exciting light give rise to localized surface plasmons responsible for an enhancement of the local electric field and SERS effect, allowing a wide range of applications in chemistry, biology and nanotechnology. Multifunctional bridging ligands can be employed for simultaneously binding metal ions and surface atoms. The attractive point of this approach is the possibility of exploiting the charge controlled stabilization by the metal complexes, while imparting new characteristics and properties to the modified nanoparticles. As a matter of fact, a new, exciting field of coordination chemistry can be envisaged, combining metal nanoparticles and metal complexes, in the light of supramolecular and surface plasmon resonance effects.

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“…Surface modification of the synthesized AuNPs was performed with the 1:1 mixture of methyl-PEG 4 -thiol and carboxy-PEG 12 -thiol (total, 100 μM), which was added to the citrate-stabilized AuNP solution (final, 50 nM). Since the used 5-nm AuNP is estimated to have 3,858 Au atoms in total and 984 Au atoms at its surface based on the reported calculation method [37,38], the 2,000:1 ligand-to-AuNP molar ratio was used to ensure the complete surface modification of AuNPs. After 2 h of incubation under convection, the carboxy-modified AuNPs were purified using an Amicon® Ultra Centrifugal Filter Unit (50 kDa, MWCO) and centrifugation (8,000×g for 10 min).…”

Section: Synthesis Of Aunpsmentioning

confidence: 99%

Gold nanoparticle-based fluorescence quenching via metal coordination for assaying protease activity

et al. 2012

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We report a gold nanoparticle (AuNP)-based fluorescence quenching system via metal coordination for the simple assay of protease activity. Carboxy AuNPs (5 nm in core diameter) functioned as both quenchers and metal chelators without requiring further modification with multidentate ligands; therefore, they were strongly associated with the hexahistidine regions of dye-tethered peptides in the presence of Ni(II) ions, leading to notable fluorescence quenching over the varying molar ratios of dye to AuNP. Upon the addition of matrix metalloproteinase-7 (MMP-7), the fluorescent intensity was efficiently recovered in one-pot mixture especially at 10:1-100:1 molar ratios of dye to AuNP. Consequently, the dequenching degree was dependent on the MMP-7 concentration in a hyperbolic manner, ranging from as low as 10 to 1,000 ngmL −1. In this regard, we anticipate that the developed system will give us a general way to construct nanoparticle-dye conjugates and will find applications in the analyses of many other proteases mediating significant biological processes with low background and high sensitivity.

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Luminescent nanobeads: attachment of surface reactive Eu(iii) complexes to gold nanoparticles

Abstract: Gold nanoparticles were used as a scaffold to assemble multiple tailor-made europium(III) complexes yielding water-soluble gold nanoparticles that display red, Eu(III), luminescence.

Cited by 128 publications

References 29 publications

pH-controlled delivery of luminescent europium coated nanoparticles into platelets

pH-controlled delivery of luminescent europium coated nanoparticles into platelets

The coordination chemistry at gold nanoparticles

Gold nanoparticle-based fluorescence quenching via metal coordination for assaying protease activity

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