Probing the Effect of Post-Synthesis Grafting on Guest−Host Interactions in Sol−Gel Silica with Single-Molecule Mobility and Photostability

2009 ◽  
Vol 113 (50) ◽  
pp. 21130-21138 ◽  
Author(s):  
Qiong Lei ◽  
Wai Tak Yip
Keyword(s):  
Single Molecule ◽  
Sol Gel ◽  
Host Interactions ◽  
Post Synthesis

Photophysical Properties of CdS Nanoparticles in Thin Films for Opto-Chemical Sensing

2004 ◽  
Vol 820 ◽  
Author(s):  
Elena A. Guliants ◽  
Barbara A. Haruff ◽  
James R. Gord ◽  
Christopher E. Bunker
Keyword(s):  
Thin Films ◽  
Organic Compounds ◽  
Protective Coatings ◽  
Photophysical Properties ◽  
Sol Gel ◽  
Liquid Solution ◽  
Optical Signal ◽  
Cds Nanoparticles ◽  
Trap States ◽  
Post Synthesis

AbstractIn recent years, II-VI compound semiconductor nanoparticles synthesized in a liquid solution have been shown to possess unique optoelectronic properties which are highly attractive for the fabrication of various sensors based on the optical signal readout scheme. The challenge has been to immobilize these nanoparticles into films on solid surfaces, i.e. on a chip, so that they do not suffer any property deterioration as a sensing medium. In the presented work, synthesis of CdS nanoparticles in reverse micelle solution using AOT surfactant as a stabilizer has led to particles with relatively bright photoemission identified as originating from both shallow and deep traps inside the bandgap. Moreover, slightly altering the preparation procedure has produced samples with two distinctive crystal structures. Both types of CdS nanoparticles suspended in commonly utilized solvents such as chloroform and hexane were subject to chemical quenching when various organic compounds were introduced into the solution, demonstrating the sensitivity of trap states to their chemical environment. However, the two structures have shown very different optical properties. While post-synthesis treatment had no effect on one type of particle, the other type was able to undergo a photochemical reaction via prolonged UV irradiation, which resulted in an increased luminescence quantum yield ÖL from 2% to 14%. The same particle type was also responsive to thermal treatment, showing even higher values of ÖL (∼40%). The CdS/AOT particles have been cast into thin films by spin-coating on a Si wafer. Coating parameters have been investigated in order to achieve optimal control over the film thickness, uniformity, overall film durability, etc. These nanostructured films capped with various porous polymeric and sol-gel protective coatings were exposed to a series of organic compounds. Photoluminescence data collected for these samples served for identification of the compounds and their concentrations. This paper offers the discussion of photophysical response in CdS nanoparticle-based thin films with respect to development of novel nanostructured opto-chemical sensors.

Lipase Immobilized within Novel Silica-based Hybrid Foams: Synthesis, Characterizations and Catalytic Properties

2010 ◽  
Vol 1272 ◽  
Author(s):  
Nicolas Brun ◽  
Annick Babeau ◽  
Victor Oestreicher ◽  
Hervé Deleuze ◽  
Clément Sanchez ◽  
...  
Keyword(s):  
Cell Hybrid ◽  
High Stability ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Batch Process ◽  
Covalent Immobilization ◽  
Open Cell ◽  
Sol Gel Process ◽  
Post Synthesis ◽  
Hybrid Foams

AbstractThe covalent immobilization of crude lipases within silica-based macroporous frameworks have been performed by combining sol-gel process, concentrated direct emulsion, lyotropic mesophase and post-synthesis functionalizations. The as-synthesized open cell hybrid monoliths exhibit high macroscopic porosity, around 90 %, providing interconnected scaffold while reducing the diffusion low kinetic issue. The entrapment of enzymes in such foams deals with a high stability over esterification and transesterification batch process catalysis.

Light Harvesting Molecular Assemblies in the Design of Highly Luminescent Sol-Gel Derived Glasses

1990 ◽  
Vol 180 ◽  
Author(s):  
Joel I. Dulebohn ◽  
Béatrice Van Vlierberge ◽  
Kris A. Berglund ◽  
Ronald B. Lessard ◽  
Jeong-a Yu ◽  
...  
Keyword(s):  
Sol Gel ◽  
Lanthanide Complex ◽  
Molecular Assembly ◽  
Electronic Energy ◽  
Lanthanide Ion ◽  
Europium Ion ◽  
Host Interactions ◽  
Porous Networks ◽  
Molecular Composites ◽  
Intense Luminescence

ABSTRACTSol-gel derived molecular composites exhibiting intense luminescence, induced from efficient energy transduction processes, have been prepared. The composites are comprised of an Eu3+⊂ 2.2.1 cryptate complex or native Eu3+ ion embedded in sol-gel derived titania glass films. The titania glasses contain interconnected porous networks that permit the diffusion of exogenous substrates, such as the salts of benzoic and 4-tert-butylbenzoic acids, through the film. Interaction of the substrate with the embedded lanthanide complex is indicated by enhanced luminescence from the lanthanide ion. The carboxylic acid salts whose electronic excited states are produced upon capture of incident photons, undergo facile transfer of their electronic energy to the lanthanide ion. By monitoring europium ion luminescence, the diffusion constants of the benzoate and 4-tert-butylbenzoate salts have been measured. Although the diffusion of the 4-tert-butylbenzoate is slower than that of benzoate, the overall higher sensitivity of the former is consistent with hydrophobic guest-host interactions. These new molecular composites relying on the immobilization of an absorption-energytransfer- emission molecular assembly in porous, optically transparent ceramic glasses may be useful in the design of practical sensing devices.

scholarly journals Macrophage-like THP-1 cells show effective uptake of silica nanoparticles carrying inactivated diphtheria toxoid for vaccination

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Xinyue Huang ◽  
Danielle Paixão Cavalcante ◽  
Helen E Townley
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Porous Silica ◽  
Diphtheria Toxoid ◽  
Similar Distribution ◽  
Antigen Delivery ◽  
Before And After ◽  
Post Synthesis

AbstractNanoparticles may be used in vaccinology as an antigen delivery and/or an immunostimulant to enhance immunity. Porous silica has been identified as an effective adjuvant for more than a decade, and we have therefore investigated the take up rate by an immortalized macrophage-like cell line of a number of mesoporous silica nanoparticles (MSNPs) with differing diameter and pore size. The MSNPs were synthesized using a sol-gel reaction and post-synthesis removal of the template. The MSNPs showed a clear distribution in take up rate peaking at 217 nm, whereas a comparison with solid spherical nanoparticles showed a similar distribution peaking at 377 nm. The MSNPs were investigated before and after loading with antigen. Diphtheria toxoid was used as a proof-of-concept antigen and showed a peak macrophage internalization of 53.42% for loaded LP3 particles which had a diameter of 217.75 ± 5.44 nm and large 16.5 nm pores. Optimal MSNP sizes appeared to be in the 200–400 nm range, and larger pores showed better antigen loading. The mesoporous silica particles were shown to be generally biocompatible, and cell viability was not altered by the loading of particles with or without antigen.

scholarly journals Facile Sol-gel Synthesis of Porous Silicas Using Poly(propylene)imine Dendrimers as Templates

2000 ◽  
Vol 15 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
Gustavo Larsen ◽  
Edgar Lotero ◽  
Manuel Marquez
Keyword(s):  
Single Molecule ◽  
Sol Gel ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Template Removal ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Argon Adsorption ◽  
Poly Propylene ◽  
Sol Gel Synthesis

Commercially available poly(propylene)imine (DAB-Am-32 and DAB-Am-64) dendrimers were used as single-molecule templates to tailor the porosity of silicas via a nonacidic sol-gel method. X-ray diffraction on both the as-prepared (oven-dried at 373 K) and the calcined (833 K) materials revealed that modest contraction took place on template removal and that the cavities created did not achieve three-dimensional ordering under the current synthesis conditions. Transmission electron microscopy of “Pt-stained” samples supported this picture. A modified Horvath–Kawazoe analysis of the argon adsorption isotherms indicated that DAB-Am-64 is a much more effective template than DAB-Am-32. Pyrolysis and oxidation protocols for template removal are also presented.

scholarly journals Biotrophic interactions disentangled: In situ localisation of mRNAs to decipher plant and algal pathogen – host interactions at the single cell level

2018 ◽  
Author(s):  
Julia Badstöber ◽  
Claire M. M. Gachon ◽  
Jutta Ludwig-Müller ◽  
Adolf M. Sandbichler ◽  
Sigrid Neuhauser
Keyword(s):  
Single Molecule ◽  
Plasmodiophora Brassicae ◽  
Plant Host ◽  
Host Interactions ◽  
Ectocarpus Siliculosus ◽  
Expression Of Genes ◽  
Algal Host ◽  
Microbe Interactions ◽  
Genome Model ◽  
Plant Pathogen Interactions

SummaryPlant-pathogen interactions follow spatiotemporal developmental dynamics where gene expression in pathogen and host undergo crucial changes. It is of great interest to detect, quantify and localise where and when key genes are active or inactive. Here, we adapt single molecule FISH techniques to demonstrate presence and activity of mRNAs using phytomyxids in their plant and algal host from laboratory and field materials. This allowed to monitor and quantify the expression of genes from the clubroot pathogen Plasmodiophora brassicae, several species of its Brassica hosts, and of several brown algae, including the genome model Ectocarpus siliculosus, infected with the phytomyxid Maullinia ectocarpii. We show that mRNAs are localised along a spatiotemporal gradient, thus providing proof-of-concept of the usefulness of these methods. These methods are easily adaptable to any interaction between microbes and their algal or plant host, and have the potential to increase our understanding of processes underpinning complex plant-microbe interactions.

scholarly journals SMRT sequencing of the full-length transcriptome of the white-backed planthopper Sogatella furcifera

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9320
Author(s):  
Jing Chen ◽  
Yaya Yu ◽  
Kui Kang ◽  
Daowei Zhang
Keyword(s):  
Single Molecule ◽  
Developmental Stages ◽  
Virus Transmission ◽  
Full Length ◽  
Transcriptome Data ◽  
Smrt Sequencing ◽  
Sogatella Furcifera ◽  
Consensus Sequences ◽  
Host Interactions ◽  
Ssr Analysis

The white-backed planthopper Sogatella furcifera is an economically important rice pest distributed throughout Asia. It damages rice crops by sucking phloem sap, resulting in stunted growth and plant virus transmission. We aimed to obtain the full-length transcriptome data of S. furcifera using PacBio single-molecule real-time (SMRT) sequencing. Total RNA extracted from S. furcifera at various developmental stages (egg, larval, and adult stages) was mixed and used to generate a full-length transcriptome for SMRT sequencing. Long non-coding RNA (lncRNA) identification, full-length coding sequence prediction, full-length non-chimeric (FLNC) read detection, simple sequence repeat (SSR) analysis, transcription factor detection, and transcript functional annotation were performed. A total of 12,514,449 subreads (15.64 Gbp, clean reads) were generated, including 630,447 circular consensus sequences and 388,348 FLNC reads. Transcript cluster analysis of the FLNC reads revealed 251,109 consensus reads including 29,700 high-quality reads. Additionally, 100,360 SSRs and 121,395 coding sequences were identified using SSR analysis and ANGEL software, respectively. Furthermore, 44,324 lncRNAs were annotated using four tools and 1,288 transcription factors were identified. In total, 95,495 transcripts were functionally annotated based on searches of seven different databases. To the best of our knowledge, this is the first study of the full-length transcriptome of the white-backed planthopper obtained using SMRT sequencing. The acquired transcriptome data can facilitate further studies on the ecological and viral-host interactions of this agricultural pest.

A comparison of post-synthesis alumination and sol-gel synthesis of MCM-41 with high framework aluminum content

1999 ◽  
Vol 27 (2-3) ◽  
pp. 231-242 ◽  
Author(s):  
L.Y. Chen ◽  
Z. Ping ◽  
G.K. Chuah ◽  
S. Jaenicke ◽  
G. Simon
Keyword(s):  
Aluminum Content ◽  
Sol Gel ◽  
Post Synthesis ◽  
Sol Gel Synthesis ◽  
Mcm 41
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