查看更多>>摘要：Fe~(3+) Herein, a bifunctional 3D porous metal-organic framework (Zn-MOF) was synthesized based on the sol-vodiermal reaction of tri(p-carboxyphenyl)phosphane oxide (H3L) and Zn salts, and characterized by powder X-ray diffraction (PXRD), diermogravimetric (TG), Infrared (IR), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). The results show that Zn-MOF has high stability and its specific surface area and pore size are 102.36 m~2 g~(-1) and 2.94 nm, respectively. Meanwhile, Zn-MOF exhibited excellent adsorption performance for Congo red (CR) and Methyl orange (MO) dyes. The adsorption of CR dyes by Zn-MOF is mainly due to the sedimentation caused by gravity of large molecules formed by hydrogen bonding between-NH2 in CR dye molecules and u3-OK in Zn-MOF, while the adsorption of MO by Zn-MOF is mainly attributed to that the larger pore size of Zn-MOF is conducive to MO dye molecules into die channels of Zn-MOF. At die same time, a series of fluorescence experiments showed diat Zn-MOF can also sensitively recognize Fe~(3+) ion in aqueous medium widi the limit of detection of 0.09716 μM, which is inferior to die previously reported values. Furthermore, the recognition mechanism of Zn-MOF for Fe~(3+) ion is mainly ascribed to the internal filtering effect (IFE) by the characterization of PXRD, UV-vis and fluorescence lifetime.
查看更多>>摘要：The green synthesis of a Zn-abietate complex obtained from Pirms Ettiottii resin exhibiting outstanding antibacterial properties is reported. The synthesis method used resin from Pinus from reforestation, and an aqueous solution of ZnS04 at a mild temperature (80 °C), without the use of organic solvents, thus giving a green character and with an antibacterial action to the compound. Spectroscopic, analytical, morphological, and structural characterization were consistent with an octahedral complex involving three carboxylate ligands per metal ion. The complex exhibits good thermal stability for practical applications. XPS results confirmed the presence of zinc atoms with oxidation state Zn~(2+). Colorimetric measurements expressed by the CIE L*a*b* method showed values characteristic of a slightly yellowish white pigment. The antibacterial efficiency was evaluated using the JIS Z 2801: 2010 standard, for 10% and 20% (w/w) of Zn-abietate in commercial white paint, leading to high inhibition (>99.99%) against Staphylococcus aureus and Escherichia coli. Because of its high antibacterial efficiency, the pigment has a great potential to be explored in paints for home and hospital environments.
查看更多>>摘要：Because of the advantages of low cost, stability and easy synthesis, poly(3-hexylthiophene) (P3HT) was the most classic photovoltaic polymer and promoted the rapid progress of fullerene-based organic solar cells (OSCs) during 2005-2015. In comparison with A-D-A type non-fullerene acceptors (NFAs), A2-A1-D-A1-A2 type molecules can realize higher open-circuit voltage (Voc) and also match well with P3HT. Hence, here we modified the classic A2-A1-D-A1-A2 type NFA of BTA3 by altering the side chains at three different positions, and synthesized five new materials of BTA3b-3f to investigate the structure-properties relationship. By fine-tuning the side chains at middle D unit, BTA3b, BTA3c and BTA3d show totally different power conversion efficiencies (PCEs) of 5.95, 3.80 and 4.74% respectively, which demonstrate the modification of D unit can significantly influence the intermolecular interaction. On the other hand, with the modulation of side chains at A1 and A2 units, BTA3e and BTA3f show relatively high PCEs of 5.48 and 6.15% respectively. Our results indicate the systematical side chain engineering for A2-A1-D-A1-A2 type NFAs play a vital role to improve the photovoltaic performance of P3HT-based OSCs.
查看更多>>摘要：The fluorescent nanomaterials based on rare earth metal complexes have become one of the promising candidates for biomedical applications due to their unique optical properties. However, direct utilization of these rare earth complexes in biological systems is challengable for their poor water solubility. In this work, an ultrasonic treatment-assisted crosslinking reaction was developed for the first time to synthesize the fluorescent amphiphilic copolymers (named as Eu (TTA)3phen-HCCP-PEG), in which the hydrophobic europium complexes (Eu (TTA)3phen-NH2) and hydrophilic polyethylene glycol were conjugated together using hexa-chlorocyclotriphosphazene (HCCP) as crosslinking agent. The reaction could be occurred uner room temperature, mild reaction conditions without using catalysts. Owing to the amphiphilicity of Eu (TTA)3phen-HCCP-PEG, fluorescent nanoparticles can be formed in aqueous solution. Thereinto, the uptake behavior of Eu (TTA)3phen-HCCP-PEG by cells and cell toxicity testing were also utilized to evaluate their potential applications in biomedical fields. Results demonstrated that these fluorescent nanoparticles are of small size, high water dis-persibility and low toxicity. The above results implied that Eu (TTA)3phen-HCCP-PEG could be potentially for biological imaging and imaging-guided drug delivery etc.
查看更多>>摘要：Lysosomal pH plays indispensable roles in regulating the activity of lysosomal hydrolases, and is involved in crucial biological procedures including autophagy. Fluorescent probes for lysosomal pH were significant molecular tools to investigate lysosomal pH regulation. In this work, we have designed a new fluorophore to respond to pH in a ratiometric manner based on intramolecular charge transfer (ICT) mechanism. By modifying different alkyl chains on the dye, we have obtained a novel ratiometric probe for lysosomal pH with optimized membrane permeability. The probe could stain lysosomes, and was capable of monitoring lysosomal pH in a ratiometric manner. Chloroquine (CQ) induced pH rise in lysosomes was successfully visualized with the probe. The down-regulation and subsequence up-regulation of lysosomal pH during starvation were also revealed in ratiometric manner. We firmly believe that the probe is a desirable tool to investigate lysosomal pH and promote the studies in autophagy and relative biological areas.
查看更多>>摘要：Aiming to develop new deep-red/near-infrared emitters, benzanthrone as a new acceptor moiety with a rigid molecular structure was used. For the design of target compounds phenothiazine and phenoxazine moieties with strong electron-donating ability were also used. Such combination allowed new materials demonstrating thermally activated delayed fluorescence (TADF) in the long wavelength region to be obtained. The maximum intensity of fluorescence of the solid samples of the synthesized compounds was observed at 700 nm. Electroluminescence was peaked at similar wavelength when the compounds were used as emitters for the fabrication of non-doped organic light-emitting diodes. Due to the different substitutions of benzanthrone moieties, the values of TADF lifetimes at room temperature were found to be of in the range of 291-1198 us which are directory related to their different oxygen sensing properties. Due to high sensitivity to the presence of oxygen in the atmosphere one of the obtained compounds was used for radiometric oxygen sensing. The film of molecular dispersion of phenoxazine containing compound in inert polymer ZEONEX? showed the ratio of intensity of TADF taken in vacuum and of prompt fluorescence taken under oxygen purge of 15.2. The oxygen sensitivity of the film estimated by Stern-Volmer constant was found to be of 1.6 x 10"4 ppm"1 demonstrating good reversibility. The time dependent density functional theory (DFT) calculations were used for the interpretation of the experimental results related to the structure and photophysical properties of the compounds.
查看更多>>摘要：The spectroscopic properties and tautomeric behavior of five novel Rhenium (I) tricarbonyl complexes bearing an azo ligand are presented. The organic ligand is stable in solution as the hydrazone tautomer. It remains as hydrazone in different medium conditions (solvent, concentration, pH, etc.) without the formation of detectable amounts of the azo tautomer. However, the complexation of this ligand to the strong electron-withdrawing fragment-Re(CO)3X (X = Cl~, Br~) causes tautomerism to appear in the organic moiety. Two well-defined regions in the electronic spectra for both tautomers were observed, allowing the azo/enol-keto/hydrazone equilibrium to be followed. TD-DFT calculations indicate that for the keto/hydrazone form, the main absorption band is attributed to an 1L transition. In contrast, the azo/enol species shows a major contribution of the ~1MLCT (dπ CRe)-dπ*(NN)) transition. The tautomeric equilibrium is easily shifted using solvents with different dielectric constant and hydrogen bond donor/acceptor (HBD/HBA) abilities. Also, the tautomerization process is deeply influenced by the electronic properties of the axial ligand. Therefore, this behavior represents a different strategy for the design of novel materials with optical properties. Furthermore, tautomerism is affected by the concentration of complexes and the presence of water in solvents. The acid-base behavior of these compounds in a 50% v/v ethanol-buffer system showed that the azo/enol tautomer is stabilized in acidic media. At the same time, an increase of pH promotes tautomerization toward the keto/hydrazone, followed by forming the anionic form at pH> 8.
查看更多>>摘要：Four naphthalimide-based compounds (NHA, NHB, NHC and NHD) bearing carbazide or semi-carbazide at different positions were designed and synthesized for the detection of cooper ions. The presence of copper ions caused different spectral changes of the four compounds: the fluorescence of NHA and NHB were enhanced, while that of NHC was quenched, and little spectral changes of NHD were observed. The mechanism studies reveal that: copper ions promoted the hydrolysis of the probe containing semi-carbazide group (NHA), leading to evident fluorescence enhancement with clear red-shift; while it formed complex with the probes bearing carbazide (NHB and NHC), resulting in fluorescence "turn-on" or "turn-off'. The substituted position of carbazide group in naphthalimide affected the fluorescence significantly: strong photoinduced electron transfer occurred as it at 4-position (NHB), whereas the PET process was not easy to happen as the group at imine-N (NHC). Copper ions increased the fluorescence of NHB by blocking the PET process, while it could initiate a d-PET process and quenched the fluorescence of NHC. Fluorescence bio-imaging experiments demonstrate that both NHB and NHC exhibit good cell permeability and can monitor Cu~(2+) as well as thiols in living cells.
查看更多>>摘要：Autophagy is a protective mechanism that exists in cells and plays an important role in maintaining the normal physiological morphology of cells and in the disease regulation of living organisms. Recent studies have shown that changes in lysosomal polarity can be an important indicator for assessing cellular autophagy. Thus, we developed a probe (Lyso-Pola) that is sensitive to lysosomal polarity to monitor these changes in order to assess the extent of cellular autophagy during scrap leather-induced neuroinflammation. The relationship between cellular autophagy, neuroinflammation, and scrap leather residues was also explored. The experimental results showed that the fluorescence signal of Lyso-Pola was significantly lower during cellular autophagy in two-photon confocal imaging. In addition, models of scrap leather-induced neuroinflammation in BV2 cells and mice showed that neuroinflammation can lead to the release of reactive oxygen species, which then induces cellular autophagy.
NSTL