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Coupling of Ag2CO3 to an optimized ZnO photocatalyst: Advantages vs. disadvantages
摘要： With the aim of improving the photocatalytic properties of a previously optimized zinc oxide photocatalyst, the effect of the incorporation of different amounts of Ag2CO3 on the aforementioned ZnO has been studied. For this purpose we report the synthesis, by means of simple precipitation procedures, of bare ZnO and Ag2CO3 samples as well as the coupled materials ZnO/Ag2CO3 (X) (where X = 1%, 2%, 4% and 5% in molar percentages). Both, single and coupled materials have been characterized by different techniques (XRD, XRF, N2-absorption, SEM, TEM, UV–vis/DRS and XPS). To assess the advantages or disadvantages that Ag2CO3 addition could have over the optimized ZnO, the photocatalytic properties have been established by following the photo-degradation of selected toxic molecules, both in the UV and in the visible, as well as using complementary techniques of liquid medium analyses (TOC and Atomic Emission Spectrometry with plasma ICP). Three selected substrates were chosen: Rhodamine B (RhB) as a dye, and phenol and caffeine as colourless recalcitrant toxic molecules.
关键词： Visible-Photocatalysis,Zinc oxide,Dyes,Ag2CO3,Caffeine,Phenol
更新于2025-09-11 14:15:04
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Red-Shifted Aminated Derivatives of GFP Chromophore for Live-Cell Protein Labeling with Lipocalins
摘要： Fluorogens are an attractive type of dye for imaging applications, eliminating time-consuming washout steps from staining protocols. With just a handful of reported fluorogen-protein pairs, mostly in the green region of spectra, there is a need for the expansion of their spectral range. Still, the origins of solvatochromic and fluorogenic properties of the chromophores suitable for live-cell imaging are poorly understood. Here we report on the synthesis and labeling applications of novel red-shifted fluorogenic cell-permeable green fluorescent protein (GFP) chromophore analogs.
关键词： fluorogenic dyes,fluorescence microscopy,protein-PAINT,fluorescent labeling,arylmethane dyes,GFP chromophore
更新于2025-09-10 09:29:36
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Superweak Coordinating Anion as Superstrong Enhancer of Cyanine Organic Semiconductor Properties
摘要： The superweak tetrakis(nonafluoro-tert-butoxy)aluminate coordinating anion was employed to introduce pseudo-gas-phase conditions to the 2-[5-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3-pentadien-1-yl]-1,3,3-trimethyl-3H-indolium chromophore. The resulting formation of a photoactive organic–inorganic hybrid salt has led to a highly stabilized excited state of the organic chromophore mainly due to the minimized lattice energy and Coulomb interactions. These highly beneficial features caused by the well dispersed negative charge of the anion have led to an enhanced neat spin-casted film fluorescence intensity, prolonged fluorescence lifetime, smooth thin film surfaces and a record power photovoltaic efficiency of 3.8 % when compared to organic salts of this particular chromophore containing anions with localised negative charge. Clear evidence is given that a superweak coordinating anion is an emerging key parameter in cyanine dye photochemistry. This approach can be seen as a general guideline to prepare highly efficient ionic dyes for organic semiconductor applications.
关键词： Weakly coordinating anions,fluorescence,organic photovoltaics,cyanine dyes,lattice energy
更新于2025-09-10 09:29:36
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Visible-Light Influenced Photocatalytic Activity of Polyaniline -Bismuth Selenide Composites for the Degradation of Methyl Orange, Rhodamine B and Malachite Green dyes
摘要： Polyaniline (PANI) when composited with bismuth selenide nanoflakes (Bi2Se3 NFs), a low bandgap semiconductor, reveals enhanced photocatalytic activity for degradation of organic dyes under irradiation of visible light. The composites synthesized using Bi2Se3NFs templates with different weight percentages of PANI by in-situ chemical oxidative polymerization have been used as efficient photocatalysts for degradation of anionic dye, Methyl Orange (MO), and cationic dyes, Rhodamine B (RhB) and Malachite Green (MG). Based on radical trapping experiments, the mechanism for the photocatalytic degradation of the dyes were proposed taking into account the synergistic effect of PANI with Bi2Se3NFs. The efficient visible-light active photocatalytic property of the polymer-inorganic composites is attributed to composites’ enhanced separation of photogenerated carriers compared to its individual constituents.
关键词： Photocatalysts,PANI,Bi2Se3,Visible light,Dyes,Composites
更新于2025-09-10 09:29:36
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Facile Synthesis of Carbon Nanotubes Covalently Modified with ZnO Nanorods for Enhanced Photodecomposition of Dyes
摘要： Utilizing a one-pot solvothermal procedure novel one-dimensional zinc oxide-carbon nanotube nanohybrids (ZnCT) were synthesized in alcohol-alkali solution, free of catalytic assistance. The ZnCT hybrids were prepared through covalent modification of zinc oxide nanorods (ZnO NRs) with functionalized carbon nanotubes (f-CNTs). The morphology and microstructure of as-prepared ZnCT hybrids were characterized by scanning electron microscopy (SEM), powder X-ray diffraction, Raman, X-ray photoelectron and UV-vis absorption spectroscopies. SEM images of the ZnCT hybrids indicated that the ZnOethanol NRs grew longer along the vertical radial (0001) surface and aggregated to a lesser extent than the analogous ZnOmethanol NRs. Photodegradation analysis showed that the off-white ZnCTethanol hybrid with ascendant UV-visible light absorption had displayed superior photocatalytic activity towards Rhodamine B (RhB) dyes than either pure ZnOethanol, ZnOmethanol NRs or ZnCTmethanol hybrid, among which the photocatalytic activity of ZnOethanol NRs was better than that of ZnOmethanol NRs. Raman and X-ray photoelectron spectroscopy analyses confirmed a strong interaction between f-CNTs and ZnOethanol NRs in ZnCTethanol hybrid, in which Zn ions were chemically bonded to negatively charged oxygen-containing groups at the graphene-like surface of f-CNTs. The enhanced separation lifetime of the photogenerated electron-hole observed by surface photovoltage and photocurrent measurements of the ZnCTethanol hybrid was attributed to the efficient covalent linking of Zn-O-C and close contact configuration between the f-CNTs and ZnOethanol NRs. Further controlled photodegradation and electron spin resonance (ESR) analyses revealed that the photodegradation of RhB dyes resulted from photogenerated holes, and radical species, such as ?O2?、?OH?, which were formed in-situ. Details of the photocatalytic mechanism were also explored herein.
关键词： Solvothermal synthesis,ZnO nanorods,Carbon nanotubes,Dyes,Photodegradation
更新于2025-09-10 09:29:36
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Poly(ε-caprolactone) modified organic dyes nanoparticles for noninvasive long term fluorescence imaging
摘要： Application of organic dyes is limited in biomedical fields due to the rapid self-quenching, poor stability and water solubility. In this work, polymer modified organic dyes is developed through the dyes initiating polymerization. The polymer length is studied by tuning the amount of monomer. With an optimal molecule weight of the polymer, the π–π stacking from π-conjugated organic fluorescent dyes and fluorescence quenching are inhibited, resulting in an enhancement of fluorescence intensity and photostability. Nanoparticles are further fabricated to be used for cell uptake based on the optimized organic dyes. Then, long term cellular fluorescence imaging is realized. This work highlights the potential of polymer modification to improve the performance of organic dyes and expand their applications.
关键词： Organic dyes,Fluorescence,Polymer modification,Noninvasive long term imaging
更新于2025-09-10 09:29:36
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Assessment of Gate Width Size on Lifetime-Based F?rster Resonance Energy Transfer Parameter Estimation
摘要： F?rster Resonance Energy Transfer (FRET) enables the observation of interactions at the nanoscale level through the use of fluorescence optical imaging techniques. In FRET, fluorescence lifetime imaging can be used to quantify the fluorescence lifetime changes of the donor molecule, which are associated with proximity between acceptor and donor molecules. Among the FRET parameters derived from fluorescence lifetime imaging, the percentage of donor that interacts with the acceptor (in proximity) can be estimated via model-based fitting. However, estimation of the lifetime parameters can be affected by the acquisition parameters such as the temporal characteristics of the imaging system. Herein, we investigate the effect of various gate widths on the accuracy of estimation of FRET parameters with focus on the near-infrared spectral window. Experiments were performed in silico, in vitro, and in vivo with gate width sizes ranging from 300 ps to 1000 ps in intervals of 100 ps. For all cases, the FRET parameters were retrieved accurately and the imaging acquisition time was decreased three-fold. These results indicate that increasing the gate width up to 1000 ps still allows for accurate quantification of FRET interactions even in the case of short lifetimes such as those encountered with near-infrared FRET pairs.
关键词： fluorescence lifetime,F?rster Resonance Energy Transfer (FRET),gated ICCD,near infrared (NIR) dyes,time-resolved imaging,gate width,in vivo imaging
更新于2025-09-10 09:29:36
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Near-Infrared Photoluminescence and Electrochemiluminescence from a Remarkably Simple Boron Difluoride Formazanate Dye
摘要： Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S1-S0 energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical properties were probed using cyclic voltammetry and revealed four electrochemically reversible waves. Electrochemiluminescence properties were examined in the presence of tri-n-propylamine, leading to maximum intensity at 910 nm, at least 85 nm (1132 cm?1) red-shifted compared to all other organic dyes. This work sets the stage for the development of future generations of dyes for emerging applications, including single-cell imaging, that require near-infrared photoluminescence and electrochemiluminescence.
关键词： NIR electrochemiluminescence,Electrochemistry,Formazanate ligands,Organic dyes,NIR photoluminescence
更新于2025-09-10 09:29:36
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A Spectroscopic Study of the Interaction between Cyanine Dyes with Different Skeleton Structures and Transferrin
摘要： Human serum transferrin (hTf) has been exploited as a bio-carrier for targeted drugs to cancer cells where transferrin receptors are expressed at high levels. In this study, cyanine dyes DMSA and DMSB with a similar main core structure were selected to evaluate the effects of heterocycle on binding with hTf by spectroscopic methods. Fluorescence spectral results have shown that DMSB, which contains a selenazole ring, had a strong affinity binding with transferrin, up to 104-fold higher than DMSA, which contains a thiazole ring. This difference may be attributed to the larger molecular volume of selenazole compared with DMSA. Binding distance between cyanine dyes and hTf demonstrated that the non-radioactive energy transfer mechanism was also involved in the fluorescence quenching of protein. Furthermore, DMSB-binding gave rise to a greater decrease of the α-helix content of hTf than DMSA suggesting that hTf, which shows a looser structure binding with DMSB, increased polarity around the tryptophan residues of hTf, which was confirmed by circular dichroism and synchronous fluorescence spectroscopy. The study provides a certain theoretical basis for the design of cyanine dyes as biomolecular probe to target drugs for hTf.
关键词： Human serum transferrin,Fluorescence quenching,Conformational changes,Cyanine dyes
更新于2025-09-10 09:29:36
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Nanotechnology in Water and Wastewater Treatment || Application of Semiconductor Nanoparticles for Removal of Organic Pollutants or Dyes From Wastewater
摘要： Increasing demand and shortage of pure water sources due to the rapid development of industrialization, population growth and long-term droughts have become an issue world-wide. Industrial growth produces a great variety of organic products and frequently these substances are complex to degrade. Industrial wastewater contains various chemicals especially synthetic dyes. Example, Textile industry generate large amount of wastewater derived to different processes of color impregnation in textile fibers, which has a great amount of detergents, dyes, microfiber (cellulose, wool, and synthetic fibers), and inorganic salts. This residual water, with great load pollutants, generates the contaminations of natural waters bodies. Now a day, more than 50% of dyes used in the textile industry are monoazo, diazo, and triazo dyes, considering their chemical stability (recalcitrant) and negative influence on the ecological systems, the regulations of the removal color in the factory effluent is a current issue of discussion all over the world. The presence of even very low concentrations of dyes in effluent is highly visible and degradation products of these textile dyes are often carcinogenic. These effluent wastewaters have been recognized to have high color, high BOD and COD load, as well as high dissolve organic matter (DOM) concentration. Dyes are aromatic compounds which can absorb light in the visible wavelengths range (400–700 nm). The dye molecule is a combination of a chromophore which is a part of the molecule that can absorb light, that is, the color-absorbing coordination group and a conjugated system, and a structure with alternating double and single bonds. Chromophores are containing C=C and C=O (carbonyl), and azo group -N=N- or nitro group (-NO2). A complex mixture containing various organic materials, including carbohydrates or polysaccharides, amino acids or peptides or proteins, lipids, humic substances, and anthropogenic organic pollutants is known as Dissolved organic matter (DOM). It plays critical roles both in drinking water (DWTPs) and wastewater treatment plants (WWTPs) in determining the treatment performance and the distributed water quality and it is found in everywhere. The presence of DOM not only affects the current discharge standards, but also presents significant challenges in wastewater restoration.
关键词： Wastewater,ZnO,Dyes,Fe2O3,Photocatalysis,Semiconductor Nanoparticles,Organic Pollutants,TiO2
更新于2025-09-10 09:29:36