Dyes and Pigments最新文献

Curcumin's remarkable anti-tumor action has drawn a lot of interest, however its low bioavailability, poor targeting, and poor water solubility restrict its therapeutic potential. Two fluorescent polymers based on curcumin/nido-carborane-crown ether were produced using a two-phase technique in this study: Cur/Carborane-C/SA (encapsulated with sodium alginate) and Cur/Carborane-C (without sodium alginate). Cur/Carborane-C/SA was thought to be the most promising polymer with anti-tumor properties. The drug delivery method based on the polymer created by tris (3-aminoethyl) amine (TAEA) and 18-crown ether-6 in combination with sodium alginate offers a novel approach to curcumin encapsulation technology. Nido-carborane improves the targeting of curcumin and its tumor-cell-inhibiting properties. Good fluorescence qualities were shown by Cur/Carborane-C/SA's fluorescence quantum yield of 0.119 %. According to in vitro drug release data, the polymer performed well for pH response release at 5.0. The TEM and particle size data demonstrated that curcumin produced uniformLy sized, difficult to agglomerate nanoparticles with a particle size of less than 300 nm. The polymer exhibited a substantial affinity and inhibition of HCT-116 and HeLa cells, with an inhibition rate that may reach 78.3 %, according to the findings of the cytotoxicity assay and cell imaging. As a result, it is anticipated that the produced Cur/Carborane-C/SA would provide a new pH-responsive drug carrier system for curcumin intended for use in cancer treatment.

In recent years, there has been a lot of focus on aggregation-induced emission materials, and most of the research has focused on the unidirectional conversion from ACQ (aggregation-causing quenching) to AIE (aggregation-induced emission), which inevitably requires complex chemical synthesis and cumbersome processes, and molecules with reversible ACQ and AIE conversion characteristics are rarely reported. In order to achieve a reversible conversion based on a single material between ACQ and AIE properties, we have developed a new functional material, DBPZ-2 (1,4-bis((4-(benzo[c] (Li et al., 2020; Hu et al., 2014; Song et al., 2024) [1,2,5]thiadiazol-4-yl)piperazin-1-yl)methyl)benzene). This compound exhibits AIE properties under neutral conditions, and interestingly, it exhibits significant ACQ properties when protonated, and then restores AIE properties after simple deprotonation. Furthermore, the sensitive response of DBPZ-2 to pH can be used as a fluorescent probe to monitor the changes in the pH value of cellular lysosomes, which brings hopes for future research on lysosomal biology and related diseases.

This study focuses on the synthesis and characterization of novel pH-sensitive color materials based on alizarin, (1,2-dihydroxyanthraquinone), a natural pigment with versatile properties. The polymer-based indicators were prepared by grafting poly(methyl methacrylate) (PMMA) and poly(2-hydroxyethyl methacrylate) (PHEMA) from alizarin through an ester pH-liable bond, allowing for easy tunability of their physicochemical properties. The synthesis process involved the esterification of alizarin using 2-bromo-2-methylpropionyl bromide, facilitated by triethylamine as an acid scavenger. The resulting alizarin served as a difunctional initiator for atom transfer radical polymerization (ATRP) of methyl methacrylate and 2-hydroxyethyl methacrylate. The molecular structures of the synthesized hybrids were confirmed using ¹H NMR and GPC analyses. The color characteristic, surface energy, thermal stability, and pH sensing activity of the alizarin-based hybrids were studied according to the type of grafted polymer nature as well as their degree of polymerization. PHEMA-grafted alizarin showed more rapid and more visible color changes under the influence of NH₃ vapours compared to PMMA hybrids, due to their less hydrophobic nature. Furthermore, kinetic plots demonstrated various hydrolysis rates, with PMMA hydrolysis being slower than that of PHEMA due to its stronger hydrophobic character. UV–Vis spectra and GPC traces confirmed the occurrence of hydrolysis and successful cleavage of the ester bond links between the grafted polymers and alizarin with a decrease of the molar mass by a factor of two as expected. Such behavior offers opportunities for tailoring degradation profiles and achieving specific release profiles upon application of a wide range of polymers with varied character. The designed polymer-based pigments exhibited a high ability to monitor calorimetrically the pH changes, especially in alkaline conditions. Overall, this study contributes to the broadening of the application of alizarin-based materials, paving the way for further exploration and development in the field of functional materials.

Styrylquinoline-based fluorophores 1–10 were synthesized via Knoevenagel and Pfitzinger reactions. The molecules were fully characterized and studied for the impact of their substitution patterns (A-D) on their optical and bioactivity properties. With exception of nitro substituted compounds 9-D and 10-D, all compounds were fluorescent in solution with a significant solvatochromic behavior measured in toluene, dioxane, tetrahydrofurane, ethyl acetate, dichloromethane, dimethylformamide, dimethylsulfoxide, acetonitrile, isopropanol, and methanol. The maximum wavelength of their emission ranged from 408 to 539 nm. Additionally, there was a significant variation in the photoluminescence (PL) quantum yield concerning different solvent polarities. The PL quantum yields ranged from small values, such as 1.7 % in methanol for compound 1-A, to good PL quantum yields, such as 44.4 % in dioxane for 7-C. For comparison, the quantum yield of 7-C in methanol was 3.3 %, a total range variation of 41.1 %. 4-B and 5-B with O-acetyl groups at ortho and at para position to the CC double bond, respectively, presented an interesting acidochromism with a redshift of about 102 nm in their emission bands along with a visible emitted color change from blue to green. In addition, the antimicrobial activity for all compounds and the theoretical mechanism of action of the more significant bioactive compounds were investigated. In inverse virtual screening studies, the enzymes Dehydrosqualene synthase and Squalene synthase were indicated as putative biological targets for 3-B and 4-B. Molecular docking indicated the amino acid residues critical for interaction in bacteria and fungi.

In this study, a new “AND” logic platform based on intramolecular charge transfer (ICT) and Förster resonance energy transfer (FRET) is developed for constructing a near-infrared dual-locked fluorescence probe with high resistance to pH in biological environments. Using esterase and glutathione (GSH) as representative activators, the developed dual-locked probe BBQ650-SS-ClHC-E discriminates cancer cells from normal cells. The esterase substrate in the probe blocks the ICT process, while the GSH substrate acts as a linker to connect the fluorescence part with the quencher part to induce the FRET process. The fluorescence activation at 732 nm operates as an “AND” logic that depends on the “ICT-on” and “FRET-off” states in the presence of both esterase and GSH. BBQ650-SS-ClHC-E can successfully discriminate HeLa, 4T1, and RAW264.7 cancer cells from HFL1 normal cells and 4T1 tumor-bearing cells in living mice. This new platform can be used to develop dual-locked fluorescence probes.

Butyrylcholinesterase (BChE), as a member of the cholinesterase family, is widely expressed in various tissues and cell types. Abnormal activity levels of BChE in organ systems or cells are usually associated with diseases. Therefore, developing effective methods for monitoring the distribution and activity of BChE in vivo is significant for exploring the physiological effects of BChE in organisms and improving prophylaxis, diagnosis or therapy of diseases. In this study, a dihydroxanthene-derived fluorescent probe CHQ-B with near-infrared (NIR) excitation and emission maxima was developed for visualizing endogenous BChE in vivo. This probe exhibits superior selectivity and sensitivity towards BChE, as well as low cytotoxicity and good biocompatibility to biosamples. Furthermore, efficient and robust fluorescence imaging of the distribution and activity of BChE in diabetic mouse models confirmed the high expression of BChE induced by diabetes. Results of experiments demonstrated that CHQ-B is a promising fluorescence imaging tool for exploring butyrylcholinesterase expression in organisms during researches of relationships between BChE expression and various diseases.

The first chemo- and stereoselective syntheses of hitherto unknown pyrrole-based β,β′-disubstituted ketocyanine dyes and alkyne-tethered enones through Lewis acid-catalyzed addition of pyrroles to skipped diynones (penta-1,4-diyn-3-ones) are described. The protocols feature a good substrate tolerance, mild reaction conditions, and high yields of target products. A wide synthetic utility of synthesized alkyne-tethered enones as novel building blocks is demonstrated by the synthesis of diverse pyrrole-containing compounds. The UV–vis absorption properties for selected representatives of novel adducts are studied to preliminary access their potential as photoinitiators/sensitizers in visible light induced polymerization.

The present study delineates the design and synthesis of two bipolar host materials, namely 4-(7-(9-([1,1′-biphenyl]-4-yl)-9H-carbazol-3-yl)-9,9-dimethyl-9H-fluoren-2-yl)benzonitrile (o-CzDFBN) and 4-(7-(9-([1,1′-biphenyl]-3-yl)-9H-carbazol-3-yl)-9,9-dimethyl-9H-fluoren-2-yl)benzonitrile (p-CzDFBN). By incorporating 9,9-dimethylfluorene as a π conjugated bridge, the fluorescence quantum yield, carrier mobility and balance can be improved. Both host materials have excellent thermal stability, with thermal decomposition temperature (T_d) of exceeding 390 °C and glass transition temperature (T_g) of exceeding 125 °C. Electroluminescent devices using p-CzDFBN as the host material show better performance than those based on o-CzDFBN. The maximum external quantum efficiencyof red PhOLED reaches 27.17%. The non-doped blue OLED achieves a EQE_max of 6.38%, a maximum luminance (L_max) of 20150 cd/m², a maximum current efficiency of 4.81 cd/A, and a maximum power efficiency of 5.40 lm/W. This research contributes to the development of new materials for OLEDs, potentially leading to more efficient, stable, and high-performing OLEDs.

To investigate the impact of substitution patterns on the photophysical properties of pyrene derivatives, six novel pyrene derivatives A1-A6 were synthesised by directly coupling anthracene with pyrene units. The objective was to explore the influence of strong electron-donating groups and substitution patterns on their photophysical behaviour. Experimental and theoretical studies were conducted to analyse the photophysical properties of these compounds, revealing a clear dependence on the position of substitution within the pyrene core. Analysis of molecular orbitals revealed significant contributions from both pyrene and anthracene moieties, with deviations from typical electronic distributions attributed to the presence of electron-donating groups. The energy gap values remained consistent across derivatives, contrary to previous findings involving acceptor motif substitutions. Structural analyses indicated deviations from planarity with significant changes in angles upon excitation. The emission spectra of mono- and disubstituted pyrene derivatives predominantly exhibited a single broad maximum with slight shoulders in each solvent. However, the emission spectra of the tetrasubstituted compound (A6) displayed a vibrational structure with three maxima in all solvents, reminiscent of pyrene itself but red-shifted by approximately 30 nm. Furthermore, the central maximum for compound A6 was around 20 nm blue-shifted compared to the other compounds, although its shoulder at around 440 nm corresponded to a maximum observed in other pyrene derivatives. Typically, 1,3,6,8-tetrasubstituted pyrene derivatives, compared to their disubstituted analogues, exhibited red-shifted emission maxima associated with increased π-conjugation due to additional units on the pyrene core. A comprehensive analysis was performed on the absorption and emission spectra of the pyrene derivatives in solvents of various polarities and in the solid state. The fluorescence intensity was influenced by solvent polarity, with A6 showing limited sensitivity (similar quantum efficiency of approximately 45 % in all solvents). Moreover, the quantum yield decreases with the increasing number of anthracene substituents, being the lowest for tetrasubstituted A6. Bi-exponential decay and shorter lifetimes were observed for A1-A6 compared to known compounds, with quantum yields decreasing as solvent polarity increased. In the solid state, emission peaks shifted towards longer wavelengths, with A1 exhibiting the highest quantum yield attributed to steric hindrance. At low temperatures (77 K), emission spectra displayed redshifts, and longer lifetimes were observed. Spectrometric tests in THF/water mixtures indicated luminescence quenching at higher water fractions.

Two new Zn(II) metal-organic frameworks (MOFs) {[Zn(Bpybc)_0.5 (m-BDC)(H₂O)]·2H₂O}_n (1) and {[Zn(H₂Bpybc)(BTEC)(H₂O)₂]·H₂O}_n (2) have been successfully synthesized, where 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridinium dichloride (H₂BpybcCl₂) is used to react as the predesigned ligand with two kinds of aromatic carboxylic acids (1,3-benzenedicarboxylic acid = m-H₂BDC, 1,2,4,5-benzenetetracarboxylic acid = H₄BTEC) as the secondary building linkers. Both two compounds own two-dimensional (2D) layered structures. In addition, compounds 1 and 2 display reversible photochromism, which is associated with the generation of free radicals via photoinduced electron transfer. Simultaneously, the photomodulated fluorescent properties and their potential applications in ink-less and erasable printing were also studied.