Transmission electron microscopy of unstained hybrid Au nanoparticles capped with PPAA (plasma-poly-allylamine): Structure and electron irradiation effects

Gontard, Lionel C.; Fernández, A.; Dunin-Borkowski, Rafal E.; Kasama, Takeshi; Lozano-Pérez, Sergio; Lucas, Stéphane

doi:10.1016/j.micron.2014.06.004

Cited by 8 publications

(8 citation statements)

References 59 publications

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“…Figure 3(d) shows functionalized CoFe 2 O 4 NPs coated with a layer of silicon dioxide (SiO 2 @CoFe 2 O 4 ), which contributed to an increase in the particle size to the average value of 13.1 nm. Since organic coatings can be sensitive to ionizing radiation present in conventional TEM microscopes and are known to have poor electronegative contrast of the image, SiO 2 coatings around NPs are poorly seen (Egerton et al., 2004; Gontard et al., 2014). The average thickness of the CoFe 2 O 4 surface coating of the NPs prepared in combination with the selected alkoxysilanes, estimated based on TEM images, occupies values between 1.5 and 6 nm.…”

Section: Resultsmentioning

confidence: 99%

Novel reusable functionalized magnetic cobalt ferrite nanoparticles as oil adsorbents

Hadela

Lakić

Potočnik

et al. 2020

Adsorption Science & Technology

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Magnetic nanoparticles are amongst the most promising adsorption materials for oil spill clean-up due to their high surface area, ease of functionalization with high oil affinity and facile separation after the cleaning process with an external magnetic field. In this work, we successfully synthesized magnetic cobalt ferrite nanoparticles (CoFe2O4 NPs) that were electrostatically stabilized and functionalized with various alkoxysilanes for effective oil adsorption and oil spill removal. Additionally, the adsorption capacity of CoFe2O4 NPs was determined, and the possibility of their reuse assessed. Prepared samples showed high oil adsorption capacities between 2.6 and 3.5 g of oil per g of nanoparticles and were successfully collected with an external magnet. Furthermore, the samples showed excellent properties after regeneration, as their adsorption capacity decreased by less than 3% after reuse. All the prepared samples were thoroughly characterized to better understand their behaviour and the differences in the use of various silanes were highlighted.

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Section: Resultsmentioning

confidence: 99%

Novel reusable functionalized magnetic cobalt ferrite nanoparticles as oil adsorbents

Hadela

Lakić

Potočnik

et al. 2020

Adsorption Science & Technology

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“…We are especially interested in forming single, isolated NPs by depositing them on ultramicroelectrode (UME) and determining the size and shape of the deposited particles by electrochemical methods. As imaging and characterization techniques, electrochemical methods have the advantage of not being diffraction limited and do not involve high-energy irradiation. , Moreover, they are capable of making measurements for electrodes, as they are prepared in solution and without the need for transfer to the gas phase or vacuum. In most cases one can make the measurements, as we describe in this letter, without extensive searching to find the particles even at the 1 nm level.…”

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confidence: 99%

Electrochemical Size Measurement and Characterization of Electrodeposited Platinum Nanoparticles at Nanometer Resolution with Scanning Electrochemical Microscopy

Chen

et al. 2017

Nano Lett.

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The properties of nanoparticles (NPs) are determined by their size and geometric structures. A reliable determination of NP dimension is critical for understanding their physical and chemical properties, but sizing ultrasmall particles on the order of nanometer (nm) scale in the solution is still challenging. Here, we report the size measurement of PtNP at nanometer resolution by in situ scanning electrochemical microscopy (SECM), performed with the electrochemical generation and removal of H bubble at a reasonably small distance between tip and substrate electrodes in 200 or 500 mM HClO solution. A series of different PtNPs or nanoclusters were electrodeposited and in situ measured in the solution, proving the concept of sizing ultrasmall particles using tip generation/substrate collection mode of SECM. This technique could be also used for investigations of other supported ultrasmall metal nanocluster systems.

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“…Alternatively, low‐loss EFTEM has been used to image organic coatings on gold NPs at ambient temperature with sufficient contrast without the need for staining. [ 70 ]…”

Section: Electron Microscopy Approachesmentioning

confidence: 99%

Deciphering the Structure and Chemical Composition of Drug Nanocarriers: From Bulk Approaches to Individual Nanoparticle Characterization

Chaupard

Frutos

Gref

2021

Part & Part Syst Charact

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payload's pharmacokinetics and contributed to achieve the desired pharmacological response at the target. They are now widely exploited for therapeutic purposes, including the treatment of severe diseases such as cancer and infections. [1] A plethora of natural and synthetic materials have been engineered at a nanoscopic level and explored for drug delivery (Figure 1). Liposomes, the first nanotechnology-based drug delivery system, were discovered early in the 1960s. [2] The first Food and Drug Administration (FDA)-approved nanotechnology was the liposomal Doxil formulation designed for the treatment of Kaposi's sarcoma and since then, more than twenty liposomal and lipid-based formulations have been approved by regular authorities. [3] Many other types of drug nanocarriers have been developed, including polymeric, hybrid or metal nanoparticles (NPs), nanogels, dendrimers, quantum dots, carbon nanotubes (CNTs), and micelles (Figure 1). Several nanotechnologies containing an active molecule or a drug combination, such as Onpattro and Vyxeos, were FDA-approved in recent years, demonstrating the potential of nanomedicine and the growing interest in this field. [4,5] Moreover, the FDA-approved NP-based vaccines represent a giant step in the fight against the COVID-19 pandemic. [6] Nowadays, a large variety of materials is used to prepare drug nanocarriers: i) organic compounds (lipids, synthetic or natural polymers, biomolecules); ii) inorganic materials (silica, carbon networks, metals, or metal oxides) and iii) hybrid organic-inorganic networks combining the properties of both their organic and inorganic counterparts. Generally, drug nanocarriers have a core-shell structure: i) the cores incorporate the drugs and release them in a controlled manner and ii) the shells govern the interactions with the living media (control protein adsorption, avoid recognition by the immune system, allow targeting diseased tissues and organs, confer bio-adhesion properties). Organic compounds remain the most employed materials for drug incorporation and for engineering multifunctional shells. Additionally, the presence of metals in drug nanocarriers' composition offers new functionalities, such as antibacterial or antifungal properties, [7] radioenhancement [8] or imaging abilities for personalized therapies. [9] More recently, nanoscale hybrid metal-organic frameworks (MOFs) emerged as versatile Drug nanocarriers (NCs) with sizes usually below 200 nm are gaining increasing interest in the treatment of severe diseases such as cancer and infections. Characterization methods to investigate the morphology and physicochemical properties of multifunctional NCs are key in their optimization and in the study of their in vitro and in vivo fate. Whereas a variety of methods has been developed to characterize "bulk" NCs in suspension, the scope of this review is to describe the different approaches for the NC characterization on an individual basis, for which fewer techniques are available. The accent is put on methods devoid of labelling, whi...

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Transmission electron microscopy of unstained hybrid Au nanoparticles capped with PPAA (plasma-poly-allylamine): Structure and electron irradiation effects

Cited by 8 publications

References 59 publications

Novel reusable functionalized magnetic cobalt ferrite nanoparticles as oil adsorbents

Novel reusable functionalized magnetic cobalt ferrite nanoparticles as oil adsorbents

Electrochemical Size Measurement and Characterization of Electrodeposited Platinum Nanoparticles at Nanometer Resolution with Scanning Electrochemical Microscopy

Deciphering the Structure and Chemical Composition of Drug Nanocarriers: From Bulk Approaches to Individual Nanoparticle Characterization

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