Dyes and Pigments最新文献

The development of efficient ultraviolet (UV) organic light-emitting materials and devices holds paramount significance for their practical applications. Nonetheless, attaining a short-wavelength electroluminescence peak of less than 390 nm while maintaining high color purity in non-doped devices remains a formidable challenge. In this work, we have successfully designed and synthesized two UV hybridized local and charge transfer fluorophores, specifically 4DBF-CZCN and 2DBF-CZCN, which are comprised of cyanide-modified phenylcarbazole and a weak electron donor dibenzofuran. And the properties of excited state are well regulated through the different linking site of dibenzofuran. The resulting non-doped devices exhibit not only emission peak wavelengths of 390 and 388 nm, accompanied by narrow full-width-at-half-maximums of 42 and 38 nm, respectively, corresponding to color coordinates of (0.164, 0.034) and (0.164, 0.036), but also admirable external quantum efficiencies of 3.00 % and 2.86 % at high luminance levels of 1910 and 1252 cd m⁻², respectively.

Human serum albumin (HSA) levels in the body are crucial for the accurate diagnosis of various health issues, necessitating continuous monitoring and novel detection methods. This study focused on the development and synthesis of two novel D-π-A small molecule near-infrared fluorescent probes, PTPA-B and CPTPA-B. The probes demonstrated selective detection of HSA with a rapid response time of 1 min and high sensitivity, featuring limits of detection (LOD) of 0.102 μM and 1.702 μM. Under physiological conditions, the intrinsic fluorescence of these probes is minimal due to intramolecular charge transfer (TICT). Upon entering the hydrophobic cavity of HSA, the probes exhibit red fluorescence by inhibiting the TICT process. Additionally, the probes exhibited enhanced biocompatibility in living cells and enabled fluorescence imaging of L-02 live cells. Therefore, the PTPA-B fluorescent probe serves as an effective tool for serum detection, revealing its potential applications in live cell imaging and precise clinical diagnosis.

Plant-derived natural extracts contain large amounts of polyphenolic compounds, presenting opportunities for chemical modification. The present study deals with the extraction of dye from Marigold (Tagetes erecta), a widely cultivated and commercially utilised flower, using water as an extraction medium followed by its chemical modification for sustainable synthesis of yellow dye and dyeing of polyester fabric. Phytochemical analysis and FTIR spectroscopy of the natural dye extract from Marigold flowers indicated the presence of polyphenolic flavonoids. The water-extracted natural dye was subsequently chemically modified with aniline, a primary aryl amine, via diazotisation and coupling reactions to yield a semi-synthetic natural dye with a 1.2 ± 0.3 g yield. The major constituents in the marigold natural extract and the Modified Marigold Extract (MME) dye were characterised using High-Resolution Liquid Chromatography-Mass Spectrometry (LC-HRMS). The marigold water extract contained a high concentration of Gossypetin 8-Glucoside, a yellow-coloured flavonoid compound with a mass-to-charge ratio (m/z) of 480.0904. LC-HRMS analysis further confirmed the presence of a constituent (m/z 424.0485) in the MME dye, corresponding to the predicted mass of chemically modified Gossypetin 8-Glucoside. The MME dye was subsequently employed for dyeing polyester fabric, exhibiting maximum colour strength at 10 % shade under acidic condition. The dyeing performances of the MME-dyed fabrics were evaluated in terms of fastness and post-dyeing strength. This study demonstrates a unique and novel approach to develop a yellow semi-synthetic natural dye, emphasising its potential utility for polyester dyeing.

Designing low-cost electron acceptors for effective bulk heterojunction (BHJ) organic solar cells (OSCs) is challenging. Here, we report two low-cost electron acceptors (TT-BO and TT-EH) with the same core of heptan-3-yloxylated thieno[3,2-b]thiophene, differing only in the alkylated thiophene-bridges. Both acceptors have similar low optical gaps (≈1.40 eV), but TT-EH exhibits a more ordered microstructure in thin film and higher electron mobility of 2.0 × 10⁻⁴ cm² V⁻¹ s⁻¹ compared to TT-BO (1.7 × 10⁻⁴ cm² V⁻¹ s⁻¹). After blending with the polymer donor, the TT-EH blend film shows a longer crystal coherence length of 2.4 nm for π-π stacking. Consequently, the TT-BO-based OSC achieves a 13.1 % power conversion efficiency (PCE). In contrast, the TT-EH-based OSC produces an excellent PCE of 14.2 %, the highest value among this kind of electron acceptors. This work offers a new insight into designing low-cost electron acceptors for efficient OSC.

Four new organic D-π-A fluorophores consisting of different electron donors (carbazole and diphenylamine) and acceptors (4,5-dicyanoimidazole and 5,6-dicyanobenzo[d]imidazole), i.e., DCI-Cz, DCI-TPA, DCBI-Cz and DCBI-TPA, were synthesized to obtain deep-blue organic light-emitting diodes (OLEDs). These compounds exhibited good solubility and excellent thermal stability as well as strong deep-blue and blue emission in solution and solid states. With mCP (1,3-di(9H-carbazol-9-yl)benzene) as the host material, the doped devices with a configuration of ITO/PEDOT:PSS (30 nm)/mCP:dopant (x wt%) (25 nm)/TPBi (35 nm)/Liq (2 nm)/Al (150 nm) were fabricated by solution-processing the emitting layers to evaluate their electroluminescence (EL) performances. The devices using the blend of mCP with DCI-TPA as emitting layers exhibited the best electroluminescent performance with a maximum external quantum efficiency (EQE_max) of 4.39 % and a maximum current efficiency of 3.04 cd/A.

Singlet fission (SF) process has attracted growing attention because of its potential capability to overcome the Shockley−Queisser limit on solar cells. So the raising of new molecule with SF character is crucial for its widespread application. In this work, the structure-property relationships of series of boron and nitrogen para-substituted (para-BN-BN and para-BN-NB) anthracene (A-n and A′-n), tetracene (T-n and T′-n), pentacene (P-n and P′-n) and hexacene (H-n and H′-n) are studied to propose novel strategy of designing SF molecule. Among these structures, the number (n) of central rings between para-(BN)₂-substituted six-membered rings can efficiently adjust the area of aromaticity, the diradical characters, which provide the low-lying T1-state energy and further favoring the availability of efficient SF molecules. We hope present work can provide novel design strategies toward the discovery of bright SF chromophores for the application to efficient organic solar cells.

This study presents the synthesis and comprehensive characterization of a novel azo dye derived from 2-(5-amino-1,3,4-thiadiazol-2-yl) phenol (1a). The synthesis was initiated by reacting salicylic acid with thiosemicarbazide in the presence of phosphorus oxychloride (POCl₃), yielding an 89 % conversion to compound 1a. The subsequent diazotization and coupling of 1a under alkaline conditions led to the formation of the azo dye (1b). Structural elucidation was confirmed through Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The incorporation of the 1,3,4-thiadiazole ring is significant due to its known influence on enhancing dye stability, reactivity, and potential biological activities, while the salicylic acid moiety contributes to the dye's pH responsiveness. A notable pH-dependent color transition from yellow (pH < 6.0) to red (pH > 8.0) was observed, driven by protonation-induced resonance changes. Computational studies, including Frontier Molecular Orbital (FMO) analysis, revealed a Highest Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) gap of 1.94 eV, indicating efficient electronic transitions critical for its color properties. Molecular Electrostatic Potential (MEP) and Fukui function analyses provided further insights into the dye's reactivity and potential applications. The dyeing properties were rigorously assessed through K/S values, CIELAB color space, and fastness properties on cotton fabric, demonstrating varied color depths and hues influenced by different mordants, with copper and manganese significantly enhancing color intensity. Colorfastness tests revealed good to fair durability, with untreated fabrics showing optimal performance. This thorough characterization underscores the promising potential of this newly synthesized azo dye for applications in pH-responsive textiles and functional materials, highlighting its relevance for advanced textile and material science applications.

Herein, we report a facile one-step solvothermal synthesis of nitrogen and sulfur co-doped fluorescent carbon dots (N,S-CDs) using benzoic acid as the carbon source and sulfonamide as the doping agent. The synthesized N,S-CDs exhibit stable photoluminescence with an impressive fluorescence quantum yield of 16.8 %. These N,S-CDs maintain their luminescent properties under various challenging conditions, including high salt concentrations, elevated temperatures, UV radiation exposure, acidic or alkaline environments, long-term storage, and different solvents. Notably, the photoluminescence of N,S-CDs is excitation-wavelength dependent, with emission wavelengths tunable from 470 nm to 585 nm. Furthermore, the N,S-CDs display distinct fluorescent hues in aqueous and ethanolic media, presenting a novel dual-switch anti-counterfeiting ink system. Leveraging the sensitivity of N,S-CDs to gentamicin, we have developed a facile and rapid detection method for this antibiotic, which has been successfully applied to the analysis of authentic milk samples. This research contributes a novel and efficient protocol for the fabrication of high-performance carbon dots, thereby expanding their potential applications in food analysis and anti-counterfeiting technologies.

4-Hydroxybenzoic acid is one of the important metabolism biochemical markers of the urine in gastric cancer patients. In this work, a fluorescence sensor based on N,S-doped carbon dots conjugated molecular imprinting polymers (N,S-CDs@SiO₂@MIPs) was prepared to detect4-hydroxybenzoic acid. The novel fluorescence sensor in response to 4-hydroxybenzoic acid ranged from 0 to 100 μmol/L, with a detection limit of 1.27 μmol/L. Furthermore, 4-hydroxybenzoic acid demonstrated strong fluorescence quenching capability on our fluorescence sensor, with the fluorescence quenching mechanism involving a combined effects of dynamic quenching and electron transfer. Lastly, the N,S-CDs@SiO₂@MIPs were applied to analyze 4-hydroxybenzoic acid inhuman urine samples with high accuracy. The findings showed that N,S-CDs@SiO₂@MIPs sensor might have high potential for effectively, selectively, accurately diagnosing gastric cancer patients.

The transformation of normal cells into cancer cells is a complex process, often accompanied by changes in the cellular microenvironment. As two key parameters of the cellular microenvironment, viscosity and pH have the potential to serve as cancer markers. Therefore, their simultaneous detection is of great significance for a more accurate understanding of cancer occurrence, development, metastasis, and treatment. To achieve dual detection of viscosity and pH, various fluorescence molecules have been designed, which can be classified into the following categories based on their sensitive sites: amine, phenolic hydroxyl, spiro-oxazolidine, and spiropyran. In addition to systematically comparing the design strategies, sensing mechanisms, and biological applications of these probes, this paper also highlights their limitations and potential future avenues of exploration. This may facilitate the design of more powerful fluorescent probes for diagnosing related diseases.