Silica Nanobubbles Containing an Organic Dye in a Multilayered Organic/Inorganic Heterostructure with Enhanced Luminescence

Lal, Manjari; Lévy, Laurent; Kim, K. S.; He, Guang S.; Wang, X.; Min, Yong; Pakatchi, S.; Prasad, Paras N.

doi:10.1021/cm000178k

Cited by 96 publications

(53 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[24] Biodegradable polymeric matrices have been found promising for the oral delivery of molecules over a sustained period of time at desirable doses. The use of microspheres made of natural polymers, such as cellulose, [25] gelatin, [26] chitosan, [27] and alginate, [28] as well as polymers made from naturally occurring monomers, such as lactic and glycolic acids, has been widely reported. [29] The polymerization of dispersed monomers is achievable by various methods, including emulsion, suspension, and dispersion techniques, while some commonly employed linear polymer preparation methods include solvent evaporation and spray-drying.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Robust, Non‐Cytotoxic, Silica‐Coated CdSe Quantum Dots with Efficient Photoluminescence

2005

View full text Add to dashboard Cite

Near-monodisperse semiconductor quantum dots (QDs) have been synthesized by wet-chemical methods for fluorescent biological labels [1±5] and light-emitting devices.[6±8] Organic capping of QDs with surfactants can provide electron passivation and form a barrier against aggregation of crystallites. Typically, CdSe QDs capped with trioctylphosphine oxide (TOPO) have a quantum yield (QY) of~10 % at room temperature. [9] Coating of CdSe QDs with semiconductors of larger bandgaps (such as ZnS) has been shown to improve the photoluminescence QY to over 60 % by passivating the surface non-radiative recombination sites.[10] While the assynthesized QDs are stable in non-aqueous solution, their photophysical behavior is affected by the use of other solvents, ligands, and environments. Photobrightening and photodarkening may also be caused by the photoionization of QDs. [11] In order to improve the photostability of QDs, they need to be encapsulated within a rigid matrix. Silica is an ideal choice, and it can be applied as a coating using a versatile sol± gel process.[12]Recent advances in synthetic routes with less-toxic precursors (e.g., CdO) have made it possible to produce highly photoluminescent CdSe nanocrystals.[13±16] However, it is a real challenge to make the plain CdSe dots water-soluble while also achieving colloidal stability, photostability, efficient fluorescence, and low non-specific adsorption under aqueous biological conditions. Two main approaches exist in the literature for the design of water-soluble QDs. The first method involves an organic coating, using either polymers, [17,18] micelles, [5] or thiol groups such as mercaptoacetic acid (MAA) [2] and mercaptoundecanoic acid [19] as the linker molecules. The second method is based on the well-known silica chemistry developed for coating metal nanoparticles. [20±23] This strategy has a number of advantages over organic coating of nanoparticles. Silica acts as a robust, inert layer against the degradation of optical properties and imparts water solubility. Silica-coated (and silanized) QDs are very useful for biological applications since they allow for surface conjugation with amines, thiols, and carboxyl groups, which in turn would facilitate the linking of biomolecules such as biotin and avidin. Alivisatos and co-workers [1] first utilized the silanization approach to coat ZnS±CdSe QDs. Although this was carried out in a more-polar methanol solution using 3-mercaptopropyl trimethoxysilane (MPS), the procedure involved numerous steps and appeared to be complex to control. [24] Conversely, Rogach et al. encapsulated water-soluble CdTe QDs in 40±80 nm silica spheres through the Stöber method, but the emission spectrum was broadened with reduced intensity.[25] Using a reverse microemulsion, monodisperse silica particles can be synthesized.[26] Dyes encapsulated within silica shells showed enhanced luminescence and lifetimes due to improved chemical stability and photostability. [27] This communication describes a simple strategy for making plain CdSe QD...

show abstract

Section: Methodsmentioning

confidence: 99%

“…[27] This communication describes a simple strategy for making plain CdSe QDs (without ZnS capping) water soluble, by coating with silica. The surfactant interaction prior to silica coating allows the hydrophobic QDs to be encapsulated within the aqueous domains of the reverse microemulsion (Scheme 1).…”

mentioning

confidence: 99%

Robust, Non‐Cytotoxic, Silica‐Coated CdSe Quantum Dots with Efficient Photoluminescence

2005

View full text Add to dashboard Cite

show abstract

“…This opens the way toward synthetically challenging strategies for the creation of highly robust smart materials and devices based on either all-organic nanoarchitectures [51,52,309] (in particular for bioimaging or biomedical applications by combination of two-photon absorbers with bioactive molecules such as drugs, proteins, recognition moieties, etc.) or hybrid materials [19,65,[310][311][312] such as metal/organic, semiconductor/metallic, nanoassemblies or functionalized surfaces. Table 1: DFT methods.…”

Section: Conclusion and Future Perspectivesmentioning

confidence: 99%

Enhanced Two‐Photon Absorption of Organic Chromophores: Theoretical and Experimental Assessments

et al. 2008

View full text Add to dashboard Cite

“…14 Moreover, the solid matrix protects the dye molecules from quenchers such as oxygen and certain solutes in buffers, which likely results in more stable luminescence. 10,12,13,15 Silica is the most commonly used inorganic shelling material as it has a number of advantages over organic as well as other inorganic materials. 16,17 In particular, silica-based NPs are resistant to microbial attack, stable in aqueous solutions, nontoxic, and biocompatible.…”

Section: Introductionmentioning

confidence: 99%

Photophysical Properties of Dye-Doped Silica Nanoparticles Bearing Different Types of Dye−Silica Interactions

Kell

Tan

et al. 2009

J. Phys. Chem. C

View full text Add to dashboard Cite

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=17745c67-7bcd-486b-8b14-daecbc43474b http://nparc.cisti-icist.nrc-cnrc.gc.ca/fra/voir/objet/?id=17745c67-7bcd-486b-8b14-daecbc43474b Photophysical properties of three types of dye-doped silica nanoparticles (NPs) with different dye-silica interactions have been investigated. In two cases the dye-silica interactions are noncovalent, where tris(2,2′-bipyridine)ruthenium(II) chloride (Rubpy) is attracted to the silica network electrostatically and tetramethylrhodamine-dextran (TMR-Dex) is trapped inside the silica matrix through spatial/steric hindrance. In the third case, tetramethylrhodamine-5-isothiocyanate (TRITC) modified with 3-aminopropyltriethoxysilane (APTES) to form TMR-APTES is bound to the silica matrix covalently. Although in all three types of architectures absorption, excitation, and emission spectra show only small red-shifts (<5 nm) as compared with free dye in water, excited state emission lifetimes, quantum yields, and anisotropies vary significantly and in quite different ways between the three architectures. All three types of interactions facilitate effective encapsulation of dye within a silica network. However, covalent bonding possesses a notable advantage over the other two types of interactions as it results in a large reduction of a nonradiative relaxation rate of the embedded dye (TMR-APTES) and, thus, a large (∼3.55-fold) increase of its quantum yield.

show abstract

Silica Nanobubbles Containing an Organic Dye in a Multilayered Organic/Inorganic Heterostructure with Enhanced Luminescence

Cited by 96 publications

References 48 publications

Robust, Non‐Cytotoxic, Silica‐Coated CdSe Quantum Dots with Efficient Photoluminescence

Robust, Non‐Cytotoxic, Silica‐Coated CdSe Quantum Dots with Efficient Photoluminescence

Enhanced Two‐Photon Absorption of Organic Chromophores: Theoretical and Experimental Assessments

Photophysical Properties of Dye-Doped Silica Nanoparticles Bearing Different Types of Dye−Silica Interactions

Contact Info

Product

Resources

About