Quantification and Reactivity of Functional Groups in the Ligand Shell of PEGylated Gold Nanoparticles via a Fluorescence-Based Assay

Maus, Lisa; Spatz, Joachim P.; Fiammengo, Roberto

doi:10.1021/la900545t

Cited by 52 publications

(78 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…90 Finally, some similar behaviour has been observed in this work where the grafting density of mPEG10,000-SH was higher on 15 nm diameter Au nanoparticles and decreased slightly from 1.573 to 0.8 PEG nm -2 when the particle size increased to 65 nm in diameter (table 3). The fact that smaller Au nanoparticles display a higher density of thiol ligand attachment has been attributed to their high surface curvature.…”

Section: Quantification Of Peg Loaded Onto Gold Nanoparticles Using Tsupporting

confidence: 86%

PEGylated gold nanoparticles: polymer quantification as a function of PEG lengths and nanoparticle dimensions

et al. 2013

View full text Add to dashboard Cite

Au nanoparticles with diameters ranging between 15 and 170 nm have been synthesised in aqueous solution using a seed-mediated growth method, employing hydroxylamine hydrochloride as a reducing agent. Thiolated polyethylene glycol (mPEG-SH) polymers, with molecular weights ranging from 2100 to 51 000 g mol-1, were used as efficient particle stabilising ligands. Dynamic light scattering and zeta potential measurements confirmed that the overall mean diameter and zeta potential of the capped nanoparticles increased in a non-linear way with increasing molecular weight of the mPEG-SH ligand. Electron microscopy and thermal gravimetric analysis of the polymer-capped nanoparticles, with a mean gold core diameter of 15 nm, revealed that the grafting density of the mPEG-SH ligands decreased from 3.93 to 0.31 PEG nm-2 as the molecular weight of the ligands increased from 2100 to 51 400 g mol-1 respectively, due to increased steric hindrance and polymer conformational entropy with increase in the PEG chain length. Additionally, the number of bound mPEG-SH ligands, with a molecular weight of 10 800 g mol-1, was found to increase in a non-linear way from 278 (σ = 42) to approximately 12 960 PEG (σ = 1227) when the mean Au core diameter increased from 15 to 115 nm respectively. However, the grafting density of mPEG10 000-SH ligands was higher on 15 nm Au nanoparticles and decreased slightly from 1.57 to 0.8 PEG nm-2 when the diameter increased; this effect can be attributed to the fact that smaller particles offer higher surface curvature, therefore allowing increased polymer loading per nm2. Au nanoparticles were also shown to interact with CT-26 cells without causing noticeable toxicity

show abstract

Section: Quantification Of Peg Loaded Onto Gold Nanoparticles Using Tsupporting

confidence: 86%

PEGylated gold nanoparticles: polymer quantification as a function of PEG lengths and nanoparticle dimensions

et al. 2013

View full text Add to dashboard Cite

show abstract

“…We have previously described AuNPs passivated with mixed monolayers of PEG thiols belonging to these two classes. 26 The -amino terminated thiols 2 and 4 were used to introduce reactive amino groups in the passivation layer of the AuNPs. In that study, we established a method for determining the number of functionalizable amino groups per particle (N NH 2 ).…”

Section: Resultsmentioning

confidence: 99%

“…25 Recently, we have proposed a variant of this approach where a bioactive peptide is coupled to AuNPs passivated with mixed-monolayers of -functionalized PEG-thiols. 26 In our system, -carboxyl PEG-thiols are responsible for colloidal stabilization while a small amount of -amino PEG-thiol *Address correspondence to fiammengo@mf.mpg.de derivatives is introduced for covalent functionalization.…”

mentioning

confidence: 99%

Conjugation of Peptides to the Passivation Shell of Gold Nanoparticles for Targeting of Cell-Surface Receptors

et al. 2010

Self Cite

View full text Add to dashboard Cite

We report the preparation of gold nanoparticles (AuNPs) functionalized with the peptide-toxin conantokin-G and their selective binding to N-methyl-d-aspartate (NMDA) receptors recombinantly expressed by transfected HEK 293 cells. The AuNPs are passivated with a mixed self-assembled monolayer of ω-carboxy- and ω-amino-polyethylene glycol (PEG) thiols. We compare two different passivation systems: the alkyl-PEG600 system is characterized by a C(11)-alkyl chain between the thiol group and the PEG segment, whereas the PEG3000 system lacks this alkyl-chain. We show that only the alkyl-PEG600 passivation system allows selective conjugation of cysteine-terminated peptides to the periphery of the passivation layer via a heterobifunctional linker strategy. In contrast, using the PEG3000 passivation system, peptides are immobilized both on the passivation layer and directly on the gold surface via concurrent place-exchange reaction. We therefore recommend the use of the alkyl-PEG600 system to precisely control the number of immobilized peptides on AuNPs. In fact, we show that the number of conjugated peptides per particle can be varied with good control simply by varying the composition of the self-assembled monolayer. Finally, we demonstrate that conjugation of the conantokin-G peptide to the solvent-exposed interface of the passivation layer results in maximal binding interaction between the peptide-functionalized AuNPs and the targeted NMDA receptors on the cell surface. Conantokin G-coupled AuNP may be used to spatially restrict NMDA-receptor-blockade on neuronal surfaces.

show abstract

“…Possibly, a chromophore released by the reaction with the target analyte (Zhao et al 2002a;Maus et al 2009) has to be separated from the nanoparticles because of overlapping absorption spectra. Furthermore, binding of ligand molecules to metal nanoparticles can be probed by surface-enhanced Raman scattering (Oyelere et al 2007).…”

Section: (E) Characterizationmentioning

confidence: 99%

Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles

Sperling

Parak

2010

Phil. Trans. R. Soc. A.

1,409

1,092

View full text Add to dashboard Cite

Inorganic colloidal nanoparticles are very small, nanoscale objects with inorganic cores that are dispersed in a solvent. Depending on the material they consist of, nanoparticles can possess a number of different properties such as high electron density and strong optical absorption (e.g. metal particles, in particular Au), photoluminescence in the form of fluorescence (semiconductor quantum dots, e.g. CdSe or CdTe) or phosphorescence (doped oxide materials, e.g. Y 2 O 3 ), or magnetic moment (e.g. iron oxide or cobalt nanoparticles). Prerequisite for every possible application is the proper surface functionalization of such nanoparticles, which determines their interaction with the environment. These interactions ultimately affect the colloidal stability of the particles, and may yield to a controlled assembly or to the delivery of nanoparticles to a target, e.g. by appropriate functional molecules on the particle surface. This work aims to review different strategies of surface modification and functionalization of inorganic colloidal nanoparticles with a special focus on the material systems gold and semiconductor nanoparticles, such as CdSe/ZnS. However, the discussed strategies are often of general nature and apply in the same way to nanoparticles of other materials.

show abstract

Quantification and Reactivity of Functional Groups in the Ligand Shell of PEGylated Gold Nanoparticles via a Fluorescence-Based Assay

Cited by 52 publications

References 74 publications

PEGylated gold nanoparticles: polymer quantification as a function of PEG lengths and nanoparticle dimensions

PEGylated gold nanoparticles: polymer quantification as a function of PEG lengths and nanoparticle dimensions

Conjugation of Peptides to the Passivation Shell of Gold Nanoparticles for Targeting of Cell-Surface Receptors

Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles

Contact Info

Product

Resources

About