31005-03-5Relevant articles and documents
Photo-switchable nanoporous silica supports for controlled drug delivery
Zeleňák, Vladimír,Beňová, Eva,Almá?i, Miroslav,Halamová, Dá?a,Hornebecq, Virginie,Hronsky, Viktor
, p. 13263 - 13271 (2018)
A photo-responsive ligand 7-[(3-triethoxysilyl)propoxy]coumarin (C) was grafted on the surface of a mesoporous silica SBA-12 material. The obtained functionalized support SBA-12_C was used as an effective light-controlled storage/release system of the anti-inflammatory drug naproxen. Irradiation with UV light at 365 nm induces the photo-dimerization of the coumarin on the surface, giving a dimer connected by a cyclobutane ring, leading to pore closure. However, irradiation with UV light of a shorter wavelength, 254 nm, leads to the cleavage of the dimers, opening of the pores, and the guest drug molecules can be released from the pores. The release of the drug was studied in two types of media, a simulated body fluid at pH = 7 and a simulated gastric fluid at pH = 2. The prepared materials were characterized by high resolution transmission electron microscopy (HR-TEM), nitrogen adsorption/desorption, infrared spectroscopy (FT-IR), thermoanalytical methods (TG/DTA) and liquid and solid-state NMR spectroscopy. The amount of released drug was monitored by HPLC chromatography at defined time intervals. The samples with pores closed by coumarin dimers were tight enough to show premature release of the drug from the sample. After light-driven pore opening, the amounts of released naproxen from coumarin modified mesoporous silica were different, depending on the pH conditions of the release media.
SESEBRINIC ACID, A CINNAMIC ACID DERIVATIVE FROM SESELI SIBIRICUM
Banerjee, Sunil K.,Mukhopadhyay, Sibabrata,Gupta, Bishan D.,Singh, Kuber,Raj, Som
, p. 1817 - 1820 (1987)
A new cinnamic acid, sesebrinic acid, was isolated from the aerial parts of Seseli sibiricum; its structure was elucidated by chemical and spectral data and hemisynthesis.A number of its analogues were also synthesized. - Key Word Index: Seseli sibiricum; Umbelliferae; coumarins; sesebrinic acid; synthesis.
Realizing both selective adsorption and efficient regeneration using adsorbents with photo-regulated molecular gates
Zhu, Jing,Ding, Jia-Jia,Liu, Xiao-Qin,Tan, Peng,Sun, Lin-Bing
, p. 4006 - 4009 (2016)
A new generation of smart adsorbents was designed by grafting photo-responsive molecules onto the pore entrances of mesoporous silica. These molecules act as the gates of the mesopores, which are reversibly closed/opened upon light irradiation. Our smart adsorbents thus realize both selective adsorption and efficient desorption, which is highly expected for adsorption but impossible for traditional adsorbents with fixed pore entrances.
A fluorogenic assay for transketolase from Saccharomyces cerevisiae
Sevestre, Aurélie,Hélaine, Virgil,Guyot, Ghislain,Martin, Christine,Hecquet, Laurence
, p. 827 - 830 (2003)
In order to generate transketolase (TK) with new or improved properties by in vitro evolution, an efficient screening system is an absolute prerequisite for identifying the evolved enzyme variants. We report here an assay allowing us to detect wild type TK activity in vitro by fluorescence. We examined the use of the fluorogenic compound 1 as donor substrate of TK, which is itself non fluorescent but releases a fluorescent product: umbelliferone.
Photoresponsive cellulose paper as a molecular printboard for covalent printing
Rull-Barrull,D'Halluin,Le Grognec,Felpin
, p. 5154 - 5162 (2017)
This contribution unveils and defines the concept of covalent printing onto cellulose paper through the support of a simple and efficient strategy. A photoresponsive cellulose paper bearing disulfide functional groups was created as a molecular printboard for spatio-temporal writing through thiol-X ligation of functional inks upon light irradiation. This strategy using molecular inks in a modular way culminated with the creation of patterns with a high resolution. Hidden covalent writing to the naked eyes was developed through the use of coumarin-based inks while the use of colored inks containing a rhodamine backbone established an uncovered pH-responsive covalent printing, both strategies can potentially find applications in the formation of anti-counterfeiting devices.
A novel fluorescent functional monomer as the recognition element in core-shell imprinted sensors responding to concentration of 2,4,6-trichlorophenol
Ren, Baixiang,Qi, Huan,Li, Xiuying,Liu, Lihui,Gao, Lin,Che, Guangbo,Hu, Bo,Wang, Liang,Lin, Xue
, p. 6083 - 6089 (2018)
We have demonstrated a fluorescent functional monomer instead of the traditional functional monomers for molecularly imprinted sensors. The sensors were firstly used to selectively detect 2,4,6-trichlorophenol (2,4,6-TCP) by solid fluorescence detection without a dispersion solution. Moreover, the selectivity and anti-interference ability of the SiO2@dye-FMIPs sensor meet the requirements of a fluorescent sensor. The novel fluorescent monomer introduced into MIP is no longer just a fluorophore without recognizing ability. The fluorescence intensity of SiO2@dye-FMIPs showed a linear response to 2,4,6-TCP concentration in the range of 0-100 nM with a detection limit of 0.0534 nM. We could also demonstrate that such a system can not only get rid of the confines of traditional functional monomers and detection manner, but also improved the applications of MIPs sensors in sensing systems.
Photo-switchable membranes constructed from graphene oxide/star-PDMS nanocomposites for gas permeation control
Alrayyes, Abdalrahman U.,Hu, Yaoxin,Tabor, Rico F.,Wang, Huanting,Saito, Kei
supporting information, p. 21167 - 21174 (2021/10/05)
A novel, photo-responsive membrane based on a star-shaped polydimethylsiloxane (PDMS) polymer and graphene-based nanosheets was for the first time designed and fabricated for controlling gas permeation. The sub-60 nm thick membrane exhibited continuous photo-reversible gas permeance control when irradiated with UV light of variable wavelengths. By optimising the nanosheet loading and nanosheet-polymer interface, the defect-free membrane demonstrated a satisfactory gas separation performance towards CO2and C3H8, allowing the membrane to potentially be useful as a photoresponsive coating for applications such in modern plant cultivation technologies. The effect of the nanosheets on the photo-triggering mechanism, a [2 + 2] cycloaddition reaction, was investigated, which revealed that the presence of the nanosheets improved the polymerisation reaction, but hindered the de-polymerisation reaction. Overall, this work provides a new opportunity for the production and investigation of a new class of photo-responsive two-dimensional nanocomposite membranes for highly controlled molecular/ion sieving.
