The response of citrate functionalised gold and silver nanoparticles to the addition of heavy metal ions

Frost, Mark S.; Dempsey, Michael J.; Whitehead, Debra

doi:10.1016/j.colsurfa.2016.12.036

Cited by 56 publications

(26 citation statements)

References 44 publications

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“…The exudates not only affect oxyanions and iron (hydr) oxides but also might cause the severe colloidal mobilization of iron (hydr)oxide nanoparticles because they could stabilize the nanoparticles by complexation on the surface. For example, citrate and aspartate are known to be nanoparticle stabilizers that can be dispersed in the medium and prevent dissolution (Frost et al 2017;Phenrat et al 2018). However, the current analytical techniques and knowledge regarding nanoparticles in the soil environment are not enough to discuss the combination of various effects; thus, we should develop more advanced analytical techniques that minimize phase transition, and we should characterize the individual interactions from a complex interconnected soil ecosystem.…”

Section: Rhizodeposition Effectmentioning

confidence: 99%

Factors modifying the structural configuration of oxyanions and organic acids adsorbed on iron (hydr)oxides in soils. A review

Han

Kim

2020

Environ Chem Lett

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Oxyanions are ubiquitous in soils, organisms and the environment. Due to their unique chemical structure, oxyanions can be easily transferred into other systems. Carbonate (CO 3 2−), nitrate (NO 3 −), phosphate (PO 4 3−), silicate (SiO 4 2−) and sulfate (SO 4 2−) are the major oxyanions in organisms and the soil environment, whereas arsenate (AsO 4 3−), antimonate (SbO 4 3−), borate (BO 3 3−), selenate (SeO 4 2−), and tellurate (TeO 4 2−) are generally reported as toxic chemicals found at trace levels. Excessive oxyanions leached from soils into water have caused severe environmental problems. Here, we review the factors affecting the structural configuration of oxyanions and organic acids adsorbed on iron oxides and hydroxides. The configuration of oxyanions on iron (hydr)oxides is controlled by surface loading, pH, sample phase, competing ions and organic acids. Under conditions of low surface loading and low pH at the interface in the absence of competing ions, oxyanions with high affinity possibly form a complex with higher denticity. But an increase in pH decreases the number of sorption sites; thus, a transition from a tri-or bidentate complex to monodentate and outer-sphere complexes occurs.

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Section: Rhizodeposition Effectmentioning

confidence: 99%

Factors modifying the structural configuration of oxyanions and organic acids adsorbed on iron (hydr)oxides in soils. A review

Han

Kim

2020

Environ Chem Lett

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“…32 Evidence for PVP and mPEG functionalization on AuNPs was confirmed using FTIR, as has been previously demonstrated. 26 Surface-enhanced Raman scattering analysis also confirmed the presence of functional groups on surface-modified AuNPs.…”

mentioning

confidence: 64%

“…25 The C=O vibration at 1,637 cm -1 identified upon analysis of the citrate-stabilized AuNPs relates to the presence of sodium citrate 26 ( Figure 2). The functional groups on our AuNPs were also confirmed using surfaceenhanced Raman spectroscopy analysis ( Figure S1).…”

Section: Characterization Of Gold Npsmentioning

confidence: 99%

Polyvinylpyrrolidone-coated gold nanoparticles inhibit endothelial cell viability, proliferation, and ERK1/2 phosphorylation and reduce the magnitude of endothelial-independent dilator responses in isolated aortic vessels

Mohamed¹,

Matou‐Nasri²,

Farooq³

et al. 2017

IJN

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Background Gold nanoparticles (AuNPs) demonstrate clinical potential for drug delivery and imaging diagnostics. As AuNPs aggregate in physiological fluids, polymer-surface modifications are utilized to allow their stabilization and enhance their retention time in blood. However, the impact of AuNPs on blood vessel function remains poorly understood. In the present study, we investigated the effects of AuNPs and their stabilizers on endothelial cell (EC) and vasodilator function. Materials and methods Citrate-stabilized AuNPs (12±3 nm) were synthesized and surface-modified using mercapto polyethylene glycol (mPEG) and polyvinylpyrrolidone (PVP) polymers. Their uptake by isolated ECs and whole vessels was visualized using transmission electron microscopy and quantified using inductively coupled plasma mass spectrometry. Their biological effects on EC proliferation, viability, apoptosis, and the ERK1/2-signaling pathway were determined using automated cell counting, flow cytometry, and Western blotting, respectively. Endothelial-dependent and independent vasodilator functions were assessed using isolated murine aortic vessel rings ex vivo. Results AuNPs were located in endothelial endosomes within 30 minutes’ exposure, while their surface modification delayed this cellular uptake over time. After 24 hours’ exposure, all AuNPs (including polymer-modified AuNPs) induced apoptosis and decreased cell viability/proliferation. These inhibitory effects were lost after 48 hours’ exposure (except for the PVP-modified AuNPs). Furthermore, all AuNPs decreased acetylcholine (ACh)-induced phosphorylation of ERK1/2, a key signaling protein of cell function. mPEG-modified AuNPs had lower cytostatic effects than PVP-modified AuNPs. Citrate-stabilized AuNPs did not alter endothelial-dependent vasodilation induced by ACh, but attenuated endothelial-independent responses induced by sodium nitroprusside. PVP-modified AuNPs attenuated ACh-induced dilation, whereas mPEG-modified AuNPs did not, though this was dose-related. Conclusion We demonstrated that mPEG-modified AuNPs at a therapeutic dosage showed lower cytostatic effects and were less detrimental to vasodilator function than PVP-modified AuNPs, indicating greater potential as agents for diagnostic imaging and therapy.

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“…FTIR spectra of the LbL platforms deposited on zinc sulfide (ZnS) were also recorded. They displayed the expected vibrational modes of the three components present in the layers: CHI (3385 cm −1 , 1667 cm −1 , 1422 cm −1 and 1397 cm −1 ); CuPcS (1457 cm −1 , 1335 cm −1 , 1149 cm −1 and 1033 cm −1 ) and the COO stretch of the citrate at 1720 cm −1 ( Figure S4) [16,34]. Again, FTIR spectra were identical, regardless of the structure of the LbL films.…”

Section: Preparation and Spectroscopic Characterization Of Lbl Film Pmentioning

confidence: 96%

Biosensors Platform Based on Chitosan/AuNPs/Phthalocyanine Composite Films for the Electrochemical Detection of Catechol. The Role of the Surface Structure

Salvo-Comino

González-Gil

Rodriguez-Valentin

et al. 2020

Sensors

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Biosensor platforms consisting of layer by layer films combining materials with different functionalities have been developed and used to obtain improved catechol biosensors. Tyrosinase (Tyr) or laccase (Lac) were deposited onto LbL films formed by layers of a cationic linker (chitosan, CHI) alternating with layers of anionic electrocatalytic materials (sulfonated copper phthalocyanine, CuPcS or gold nanoparticles, AuNP). Films with different layer structures were successfully formed. Characterization of surface roughness and porosity was carried out using AFM. Electrochemical responses towards catechol showed that the LbL composites efficiently improved the electron transfer path between Tyr or Lac and the electrode surface, producing an increase in the intensity over the response in the absence of the LbL platform. LbL structures with higher roughness and pore size facilitated the diffusion of catechol, resulting in lower LODs. The [(CHI)-(AuNP)-(CHI)-(CuPcS)]2-Tyr showed an LOD of 8.55∙10−4 μM, which was one order of magnitude lower than the 9.55·10−3 µM obtained with [(CHI)-(CuPcS)-(CHI)-(AuNP)]2-Tyr, and two orders of magnitude lower than the obtained with other nanostructured platforms. It can be concluded that the combination of adequate materials with complementary activity and the control of the structure of the platform is an excellent strategy to obtain biosensors with improved performances.

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The response of citrate functionalised gold and silver nanoparticles to the addition of heavy metal ions

Cited by 56 publications

References 44 publications

Factors modifying the structural configuration of oxyanions and organic acids adsorbed on iron (hydr)oxides in soils. A review

Factors modifying the structural configuration of oxyanions and organic acids adsorbed on iron (hydr)oxides in soils. A review

Polyvinylpyrrolidone-coated gold nanoparticles inhibit endothelial cell viability, proliferation, and ERK1/2 phosphorylation and reduce the magnitude of endothelial-independent dilator responses in isolated aortic vessels

Biosensors Platform Based on Chitosan/AuNPs/Phthalocyanine Composite Films for the Electrochemical Detection of Catechol. The Role of the Surface Structure

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