Interface formation during silica encapsulation of colloidal CdSe/CdS quantum dots observed by <i>in situ</i> Raman spectroscopy

Biermann, Amelie; Aubert, Tangi; Baumeister, Philipp; Drijvers, Emile; Hens, Zeger; Maultzsch, Janina

doi:10.1063/1.4979515

Cited by 15 publications

(21 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the reaction progresses, the particles start to agglomerate, without significantly changing the nanocrystal size and distribution as observed in the UV-Vis absorption spectra (Figure 1). It was earlier demonstrated that the agglomeration rate is a strong function of the carbon chain length of the ligand, either because of the energetic barrier due to the interaction among the ligand monolayer or the repulsive potential between the two spheres, enhanced by the monolayer thickness of the ligands, as demonstrated by Biermann et al [41] Ligand exchange on the surface of the quantum dots was further investigated by thermogravimetric (TGA) and derivative thermogravimetric (DTG) analyses (Figure 3). Figure 3(a 3 Journal of Nanomaterials with the quantum dots through the carbonyl, such as OA [56][57][58].…”

Section: Resultsmentioning

confidence: 91%

“…Among many cadmium chalcogenide semiconductors, CdSe quantum dots have been widely studied in the literature [38][39][40][41][42]. Cadmium chalcogenides are well-known for their synthesis, yields, reliability, and stability.…”

Section: Introductionmentioning

confidence: 99%

“…As the reaction progresses, the particles start to agglomerate, without significantly changing the nanocrystal size and distribution as observed in the UV-Vis absorption spectra (Figure1). It was earlier demonstrated that the agglomeration rate is a strong function of the carbon chain length of the ligand, either because of the energetic barrier due to the interaction among the ligand monolayer or the repulsive potential between the two spheres, enhanced by the monolayer thickness of the ligands, as demonstrated by Biermann et al[41]. The molecular chain length (D molecule ) of OA (1.937 nm), MPA (0.409 nm), and MBA (0.596 nm) contributes to explain the behavior shown in Figures 2(b), 2(d), and 2(f) where D molecule of each ligand is compared to the dispersion of the quantum dots.…”

mentioning

confidence: 97%

See 2 more Smart Citations

3-Mercaptopropionic, 4-Mercaptobenzoic, and Oleic Acid-Capped CdSe Quantum Dots: Interparticle Distance, Anchoring Groups, and Surface Passivation

Santos

Baum

Kohlrausch

et al. 2019

Journal of Nanomaterials

View full text Add to dashboard Cite

The optoelectronic properties of quantum dots are strongly controlled by the chemical nature of their surface-passivating ligands. In this work, we present the synthesis, characterization, and surface modification of CdSe quantum dots (QDs) and their application in solar cells. CdSe QDs were capped in oleic acid (OA), 3-mercaptopropionic acid (MPA), and 4-mercaptobenzoic acid (MBA). The QDs were characterized by transmission electron microscopy (TEM), UV-Vis absorption and emission spectrophotometry, thermogravimetric analyses, and 1H and 13C NMR. From TEM analysis, it has been observed that interparticle distance can be effectively controlled by the presence of different molecular size ligands. From the 1H and 13C NMR, specific types of interactions between the Cd2+ and the ligands have been observed. Although CdSe/OA presented larger interparticle distance as compared to CdSe/MPA and CdSe/MBA, the photocatalytic oxidation of the thiol groups on the surface of the MPA- and MBA-based quantum dots resulted in poor surface stabilization, ultimately resulting in poor power conversion efficiencies which were ca. 70% smaller than that of OA-based solar cell.

show abstract

Section: Resultsmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

“…As the reaction progresses, the particles start to agglomerate, without significantly changing the nanocrystal size and distribution as observed in the UV-Vis absorption spectra (Figure1). It was earlier demonstrated that the agglomeration rate is a strong function of the carbon chain length of the ligand, either because of the energetic barrier due to the interaction among the ligand monolayer or the repulsive potential between the two spheres, enhanced by the monolayer thickness of the ligands, as demonstrated by Biermann et al[41]. The molecular chain length (D molecule ) of OA (1.937 nm), MPA (0.409 nm), and MBA (0.596 nm) contributes to explain the behavior shown in Figures 2(b), 2(d), and 2(f) where D molecule of each ligand is compared to the dispersion of the quantum dots.…”

mentioning

confidence: 97%

See 1 more Smart Citation

3-Mercaptopropionic, 4-Mercaptobenzoic, and Oleic Acid-Capped CdSe Quantum Dots: Interparticle Distance, Anchoring Groups, and Surface Passivation

Santos

Baum

Kohlrausch

et al. 2019

Journal of Nanomaterials

View full text Add to dashboard Cite

show abstract

“…The biocompatibility and the biomedical uses of QDs are highly dependent on their composition, which, besides containing heavy metals, also includes poorly biocompatible solvents employed in their synthesis [162,164,166,168,173]. This issue could be partially solved by coating QDs with a silica/MS layer able to displace the coordinated solvents while preserving [174] the QD core [175,176,177]. Unfortunately, the intrinsic toxicity associated with the forming elements and remainder solvents in their composition make them risky for in vivo biomedical applications.…”

Section: Inorganic-mesoporous Silica Nanocomposites Responsive To mentioning

confidence: 99%

Functional Mesoporous Silica Nanocomposites: Biomedical Applications and Biosafety

Castillo

Vallet‐Regí

2019

IJMS

View full text Add to dashboard Cite

The rise and development of nanotechnology has enabled the creation of a wide number of systems with new and advantageous features to treat cancer. However, in many cases, the lone application of these new nanotherapeutics has proven not to be enough to achieve acceptable therapeutic efficacies. Hence, to avoid these limitations, the scientific community has embarked on the development of single formulations capable of combining functionalities. Among all possible components, silica—either solid or mesoporous—has become of importance as connecting and coating material for these new-generation therapeutic nanodevices. In the present review, the most recent examples of fully inorganic silica-based functional composites are visited, paying particular attention to those with potential biomedical applicability. Additionally, some highlights will be given with respect to their possible biosafety issues based on their chemical composition.

show abstract

“…26,27 During the encapsulation process, the organic ligands on the surface of the QDs are substituted for hydrolyzed silica monomers resulting in a tight interaction between the QD and the silica matrix. 28 Recently developed core-shell CdSe/CdS QDs have shown superior optical properties with particularly robust emission when encapsulated in silica, even in oxidative aqueous environments. 29 The silica matrix additionally provides a convenient platform for the versatile surface functionalization of these NPs with a large variety of organosilanes.…”

mentioning

confidence: 99%

Efficient Endocytosis of Inorganic Nanoparticles with Zwitterionic Surface Functionalization

Drijvers¹,

Liu²,

Harizaj³

et al. 2019

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

PEGylation, which has traditionally been the method of choice to enhance the colloidal stability of nanostructures designed for biological applications, and to prevent non-specific protein adsorption, is now being challenged by short zwitterionic ligands. Inspired by the zwitterionic nature of cell membranes, these ligands have the potential to push forward the field of nanoparticles for nanomedicine. In this work, we report a thorough analysis of the surface chemistry of silica coated luminescent CdSe/CdS quantum dots functionalized with either PEGsilane or zwitterionic sulfobetaine-silane by quantitative nuclear magnetic resonance spectroscopy. We demonstrate the differences in the cellular uptake propensity between particles with these two ligands. While both ligands offer good colloidal stability in crowded cell culture medium, the zwitterionic functionalized nanoparticles with an optimized ligand density showed to be more easily endocytosed by HeLa cells. This approach can readily be transferred to other nanoparticle systems offering a wealth of unique properties, with great potential for intracellular bioapplications. IntroductionDiagnostic and therapy techniques in modern nanomedicine have benefited in the past decades from the growing interest and significant advancement in the development of functional nanoparticles (NPs). [1][2][3] New generation NPs have emerged as important players in the development of high contrast bioimaging and in offering novel diagnostic and therapeutic opportunities. Due to their unique properties (luminescent, magnetic, plasmonic, etc.), and in combination with specific surface functionalization, NPs have become an interesting class of materials for cell labeling, selective targeting of biomolecules, sensitive biosensing, smart drug delivery strategies and other theranostics applications. [4][5][6] To achieve their full potential, NPs developed for biological applications should meet important criteria, including a robust colloidal stability in a variety of complex environments. Indeed, the colloidal stability observed for inorganic NPs in a simple solvent system is often challenged once in dense and crowded biological media. On the other hand, for NPs specifically designed for intracellular applications, an efficient cellular uptake is also required, which is commonly achieved via endocytic pathways. 5 Several approaches have been

show abstract

Interface formation during silica encapsulation of colloidal CdSe/CdS quantum dots observed by in situ Raman spectroscopy

Cited by 15 publications

References 45 publications

3-Mercaptopropionic, 4-Mercaptobenzoic, and Oleic Acid-Capped CdSe Quantum Dots: Interparticle Distance, Anchoring Groups, and Surface Passivation

3-Mercaptopropionic, 4-Mercaptobenzoic, and Oleic Acid-Capped CdSe Quantum Dots: Interparticle Distance, Anchoring Groups, and Surface Passivation

Functional Mesoporous Silica Nanocomposites: Biomedical Applications and Biosafety

Efficient Endocytosis of Inorganic Nanoparticles with Zwitterionic Surface Functionalization

Contact Info

Product

Resources

About