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Adsorption, a crucial method for removing dyes from wastewater, has been extensively studied in the context of eliminating Acridine Orange (AO), a cationic dye, from contaminated water. This review underscores the environmental risks posed by AO, given its high toxicity, and delves into various adsorption techniques developed to eliminate it from water. It covers works on AO removal published from 1981 to April 2024, highlighting the effectiveness of different adsorbents, including natural, synthetic, composite, and nanomaterials, under varying conditions like pH, initial dye concentrations, temperature, and adsorbent dosages. Most studies on adsorption isotherms, kinetics, and thermodynamics have yielded favorable results, with common models including the Langmuir and Freundlich and pseudosecondorder kinetics. As identified by these studies, the main driving force for adsorption is electrostatic interactions between AO and the adsorbents. The review also encompasses competitive adsorption, adsorbent regeneration, alternative decontamination methods, and the pivotal role of computational research in optimizing adsorption processes. [ABSTRACT FROM AUTHOR]

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), is a highly polyphagous insect feeding on many wild host plants and a pest of economically important cultivated crops. The landscape composition plays an important role on the population dynamics of tarnished plant bugs and merits further examination to better manage populations across the agroecosystem. In this study, we evaluated the potential of eight oral biomarkers in combination with an inexpensive and portable fluorescent adapter in order to track the movement of L. lineolaris. Tarnished plant bugs from a laboratory colony were exposed to 8 biomarkers (Safranin O, Acridine Orange, Rhodamine B., Fluorescein sodium salt, Acid Fuchsin, Brilliant Blue, Fluorescent Brightener 28, and Carmoisine) contained in a 10% honey solution using three ingestion methods (dye-infused floral foam, dye-overlaid diet, and a dye-incorporated diet). At 24, 48, and 72 h post-exposure, the L. lineolaris nymphs and adults were removed from each treatment, killed by freezing and evaluated for florescence using a microscope equipped with a NightSea™ Florescence adapter under different lighting and filter combinations. The results indicated that Safranin O, Rhodamine B, and Acridine Orange are potentially useful as oral biomarkers for both nymph and adult L. Lineolaris when incorporated into a honey water solution and delivered via ingestion by floral foam, diet-overlay, or incorporated into their diet. This study provides information usable by ecologists and entomologists for to selecting biomarkers for particular life stages to address the different mobile phases of an insect life cycle. Resumen La chinche lygus, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Meridae) es un insecto altamente polífago que se alimenta de hospederos naturales y cultivos de importancia económica. El medio ambiente juega un papel importante sobre las dinámicas poblacionales de la chinche lygus, y amerita estudios más a fondo para un mejor manejo de sus poblaciones a través del ecosistema. En el presente estudio se evaluó el potencial de ocho marcadores biológicos-orales en combinación con un adaptador fluorescente portátil y fácil de adquirir con el fin de hacer el seguimiento en los movimientos de L. lineolaris. Una colonia de laboratorio de chinche lygus se expuso a 8 biomarcadores (Safranin O, Acridine naranja, Rhodamine B., Flourescein sodio sal, ácido Fuchsin, Brilliant azul, Brillante Floreciente 28, tintura Carmoisine) en una solución de agua con miel al 10%, los cuales se utilizaron tres métodos de ingestión; infusión de tintura en espuma florar, tintura superpuesta sobre la superficie de dieta y tintura incorporada en dieta. En intervalos de 24, 48 y 72 postratamiento, ninfas y adultos de L. lineolaris se removieron de cada tratamiento y se trasladaron a un congelador hasta que murieron. Los cadáveres fueron evaluados por florescencia usando un microscopio equipado con un adaptador NighSea TM fluorescente bajo diferentes combinaciones de luces y filtros. Los resultados indicaron que Safranin O, Rhrodamine B y Acridine naranja, son potencialmente útiles como marcadores biológico-orales para ninfas y adultos de L. lineolaris cuando se incorporan en agua-miel humedecida en espuma floral, solución puesta en la superficie de dieta y solución incorporada en dieta. Este estudio proporciona información útil para ecólogos y entomólogos para seleccionar marcadores biológicos para determinados estados de vida enfocados en las fases móviles del ciclo de vida de un insecto. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA) colloidal particles are nowadays extensively used in several applications and more specifically in nanotechnology. Challenges are focused on the green synthesis process leading to size‐controlled particles. In the present work, PMMA particles were successfully synthesized using tandem acoustic emulsification in water without organic solvent, and cross‐linkers. 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride (AIBA) or ammonium persulfate (APS), were used as initiators. Parameters leading to size control were clearly identified. Consequently, the cooling rate of the solution after polymerization time appears dominating. Particle size distribution was monodispersed for both initiators. A nonionic surfactant, Tween 20, was also added, leading to a decrease in size particle and an increase in synthesis yield. Depending on the chemical groups provided by the initiator, PMMA particles appear negatively or positively charged. These charges located on the particle surface led to stable particle dispersion by limiting aggregation phenomena. Tunable surface charge was confirmed across the elaboration of coatings only made of PMMA particles, using conventional techniques wherein charged species are needed (Layer‐by‐Layer assembly and electrophoretic deposition). PMMA particles were also labelled using fluorescent dyes. Fluorescein and Nile Blue A were loaded during the polymerization process to ensure a homogeneous distribution of the dyes within the particles. [ABSTRACT FROM AUTHOR]

This study focuses on derivatizing 1‐(dicyanomethylene)indan as a viscosity sensor. The indan was extended with various functionalized naphthaldehydes under a push–pull design strategy. Among synthesized derivatives, salt‐capped derivatives exhibited an excellent linearity between fluorescent intensity and viscosity (R2 = 0.99), and further investigation underscores the reversible nature of fluorescence intensity changes at two temperatures as an important trait of viscosity sensors. [ABSTRACT FROM AUTHOR]

We prepared network polysaccharide nanoscopic hydrogels by crosslinking water-soluble chitosan (WSCS) with a carboxylate-terminated maltooligosaccharide crosslinker via condensation. In this study, the enzymatic elongation of amylose chains on chitosan-based network polysaccharides by glucan phosphorylase (GP) catalysis was performed to obtain assembly materials. Maltoheptaose (Glc7) primers for GP-catalyzed enzymatic polymerization were first introduced into WSCS by reductive amination. Crosslinking of the product with the above-mentioned crosslinker by condensation was then performed to produce Glc7-modified network polysaccharides. The GP-catalyzed enzymatic polymerization of the α-d-glucose 1-phosphate monomer from the Glc7 primers on the network polysaccharides was conducted, where the elongated amylose chains formed double helices. Enzymatic disintegration of the resulting network polysaccharide assembly successfully occurred by α-amylase-catalyzed hydrolysis of the double helical amyloses. The encapsulation and release of a fluorescent dye, Rhodamine B, using the CS-based network polysaccharides were also achieved by means of the above two enzymatic approaches. [ABSTRACT FROM AUTHOR]

Virus is a kind of simple microorganism specializing in intracellular parasitics, which is one of the main pathogens causing animal and plant diseases. The development of single-virus tracking（SVT）technology makes it possible to reveal the fine process of viral life activity. SVT is a new method to study the mechanism of viral infection based on fluorescence labeling and high spatio-temporal resolution imaging, which allows the observation of the life activity of a single or multiple viruses. In recent years, the SVT technology has made great progress in the study of virus entry, replication, and intercellular transmission, providing new insights into the mechanism of virus infection. In this paper, the principle and strategy types of virus labeling are briefly introduced, and the research progress of virus fluorescence labeling in single virus tracing is summarized, especially the labeling and imaging methods of different structures of viruses, aiming to provide new ideas for optimizing labeling strategies and solving the problem of efficient labeling of different types and structures of viruses. [ABSTRACT FROM AUTHOR]

Aims To assess the efficacy of two commercially available viability dyes, 5-cyano-2,3-di-(p-tolyl)tetrazolium chloride (CTC) and 5(6)-carboxyfluorescein diacetate (CFDA), in reporting on viable cell concentration and species using an all-fibre fluorometer. Methods and results Four bacterial species (two Gram-positive and two Gram-negative) commonly associated with food poisoning or food spoilage (Escherichia coli, Salmonella enterica, Staphylococcus aureus , and Bacillus cereus) were stained with CTC or CFDA and the fibre fluorometer was used to collect full fluorescence emission spectra. A good correlation between concentration and fluorescence intensity was found for Gram-negative bacteria between 107 and 108 colony-forming units (CFU) ml−1. There was no correlation with concentration for Gram-positive bacteria; however, the information in the CTC and CFDA spectra shows the potential to distinguish Gram-negative cells from Gram-positive cells, although it may simply reflect the overall bacterial metabolic activity under staining conditions from this study. Conclusions The limit of detection (LoD) is too high in the dip-probe approach for analysis; however, the development of an approach measuring the fluorescence of single cells may improve this limitation. The development of new bacteria-specific fluorogenic dyes may also address this limitation. The ability to differentiate bacteria using these dyes may add value to measurements made to enumerate bacteria using CTC and CFDA. [ABSTRACT FROM AUTHOR]

The realization of multifunctional advanced displays with better electro-optical properties is especially crucial at present. However, conventional integral full drive-based transparent display is increasingly failing to meet the demands of the day. Herein, partitioned polymerization as a novel preparation method was introduced innovatively into polymer-dispersed liquid crystals (PDLC) for realizing a step-driven display in agreement with fluorescent dye to solve the above drawback. At first, the utilization of fluorescent dye to endow the PDLC film with fluorescent properties resulted in a reduction in the saturation voltage of the PDLC from 39.7 V to 25.5 V and an increase in the contrast ratio from 58.4 to 96.6. Meanwhile, the experimental observations and theoretical considerations have elucidated that variation in microscopic pore size can significantly influence the electro-optical behavior of PDLC. Then, the step-driven PDLC film was fabricated through the exposure of different regions of the LC cell to different UV-light intensities, resulting in stepwise voltage–transmittance (V–T) responses of the PDLC film for the corresponding regions. Consequently, under appropriate driving voltages, the PDLC can realize three different states of total scattering, semi-transparent and total transparent, respectively. In addition, the PDLC film also embodied an outstanding anti-aging property and UV-shielding performance, which makes it fascinating for multifunctional advanced display applications. [ABSTRACT FROM AUTHOR]

The fast, affordable, and standardized detection of microplastics (MP) remains one of the biggest challenges in MP research. Comparable data are essential for appropriate risk assessments and the implementation of laws and limit values. The fluorescent staining of MP in environmental samples is a possible solution to this problem. This study investigates the optimization of a sample preparation process (hydrogen peroxide digestion) and the staining process (temperature, concentration, time, surfactants as staining aids) for using a specifically developed fluorescent dye for MP detection. The optimization is performed by comparing the sample preparation process and staining of MP from different polymers and natural particles. Further, the suitability of the optimized process for the detection of fluoropolymers and tire abrasion was tested. The results show that the optimized method (increased temperature and optimized stain concentration) can detect microplastics reliably with a total sample preparation and measurement time of 2.5–3 h per sample, reaching recovery rates of 93.3% (polypropylene) to 101.7% (polyester). Moreover, two of the three tested fluoropolymers could be detected reliably. Tire abrasion could not be detected with the here presented method, as the black color leads to strong quenching. A long-term study measuring the MP pollution in the effluent of a municipal wastewater treatment plant compared the optimized and original processes and confirmed the stability of the improved method for routine measurements and contamination control. [ABSTRACT FROM AUTHOR]

Indocyanine green is a cyanine dye that displays fluorescent properties in the near-infrared region. Indocyanine green has good water solubility and can bind to plasma proteins in the body. After binding, it can display green fluorescence when irradiated by near-infrared fluorescence. Owing to its good imaging ability and low side effects, indocyanine green is widely used in the diagnosis and treatment of various tumors. Indocyanine green-assisted sentinel lymph node biopsy helps determine clean tumor boundaries, helps surgeons remove primary tumors completely, assists in microvascular anastomosis in head and neck repair and reconstruction, reduces operation time, evaluates blood perfusion to monitor flap status. In addition, indocyanine green has great potential in photodynamic therapy to specifically kill tumor cells. However, despite the benefits, studies regarding the application of indocyanine green in oral cancer are limited. Therefore, we conducted a literature review to explore the application of indocyanine green in oral cancer to benefit clinicians involved in the diagnosis and treatment of this disease. [ABSTRACT FROM AUTHOR]

Numerous agents such as near-infrared dyes that are characterized by specialized cancer imaging and cytotoxicity effects have key roles in cancer diagnosis and therapy via molecularly targeting special biological tissues, organelles and processes. In the present study, a novel fluorescent compound was demonstrated to inhibit cancer cell proliferation in a zebrafish model with slight in vivo toxicity. Further studies demonstrated selective staining of cancer cells and even putative cancer stem cells via accumulation of the dye in the mitochondria of cancer cells, compared with normal cells. Moreover, this compound was also used to image cancer cells in vivo using a zebrafish model. The compound displayed no apparent toxicity to the host animal. Overall, the data indicated that this compound was worthy of further evaluation due to its low toxicity and selective cancer cell imaging and killing effects. It could be a useful tool in cancer research. [ABSTRACT FROM AUTHOR]

The discovery of fluorescence and the development of fluorescent dyes have enriched our lives and brought important applications. As a new member of the fluorescent dye family, aggregation-induced emission materials have developed rapidly in recent years. Herein, we introduce the development history of the aggregation-induced emission phenomenon, the application of the aggregation-induced emission (AIE) materials, and the prospect of the future. [ABSTRACT FROM AUTHOR]

Cellular membranes play a key role in cell communication with the extracellular environment and neighboring cells. Any changes, including their composition, packing, physicochemical properties and formation of membrane protrusions may affect cells feature. Despite its great importance, tracking membrane changes in living cells is still a challenge. For investigation of processes related to tissue regeneration and cancer metastasis, such as the induction of epithelial-mesenchymal transition, increased cell motility, and blebbing, the possibility to conduct prolonged observation of membrane changes is beneficial, albeit difficult. A particular challenge is conducting this type of research under detachment conditions. In the current manuscript, a new dithienothiophene S,S-dioxide (DTTDO) derivative is presented as an effective dye for staining the membranes of living cells. The synthetic procedures, physicochemical properties, and biological activity of the new compound are presented herein. In addition to the labeling of the membranes in a monolayer culture, its usefulness for visualization of membranes under detachment conditions is also demonstrated. Obtained data have proven that a new DTTDO derivative may be used to stain membranes in various types of experimental procedures, from traditional 2D cell cultures to unanchored conditions. Moreover, due to the specific optical properties, the background signal is reduced and, thus, observation may be performed without washing. [ABSTRACT FROM AUTHOR]

We report the photophysical properties, self‐assembly and biological evaluation of an isothiazolanthrone‐based dye, 7‐amino‐6H‐anthra[9,1‐cd]isothiazol‐6‐one (AAT), which reveals anticancer properties and can be potentially used as dye for monitoring cell viability. The solvent‐dependent photophysical studies suggest that the emission of AAT is sensitive to environment polarity due to which interesting changes in the colored emission may be observed owing to the charge transfer (CT) processes. AAT also self‐assembles to tree‐like branched morphologies and produce, a greenish emission inside the cells when imaged after short interval (15 mins) of incubation while a red fluorescence could be noted after 24 h. Interestingly, AAT also produce differential emission inside mouse normal cells as compared to its cancer cell lines since it possess anticancer activity. The experimental observations were also validated theoretically via computational modeling. [ABSTRACT FROM AUTHOR]

In recent years, the [2.2]paracyclophane (PCP) ring has attracted extensive attention due to its features of providing not only chirality and electron-donating ability but also steric hindrance, which reduces intermolecular π–π stacking interactions and thereby improves the fluorescence properties of dyes. To date, some circularly polarized luminescence (CPL)-active small organic molecules based on the PCP skeleton have been reviewed; however, the application of the PCP ring in improving the photophysical properties of fluorescent dyes is still limited, and new molecular design strategies are still required. This review summarizes and promotes the application of PCP in fluorescent dye design, fluorescence detection, and CPL modulation. We expect that this review will provide readers with a comprehensive understanding of the PCP skeleton and lead to further improvement in fluorescent dye design. [ABSTRACT FROM AUTHOR]

Rare-earth element-free fluorescent materials are eco-friendlier than other traditional fluorescent precursors, such as quantum dots and phosphors. In this study, we explore a simple and facile solution-based technique to prepare fluorescent films, which are highly stable under ordinary room conditions and show hydrophobic behaviour. The proposed hybrid material was designed with hybrid composites that use polyvinyl butyral (PVB) as a host doped with organic dyes. The red and green fluorescent films exhibited quantum yields of 89% and 80%, respectively, and both are very uniform in thickness and water resistant. Additionally, PVB was further compared with another polymeric host, such as polyvinylpyrrolidone (PVP), to evaluate their binding ability and encapsulation behaviour. Next, the effect of PVB on the optical and chemical properties of the fluorescent materials was studied using UV spectroscopy and Fourier transform infrared spectroscopy. The analysis revealed that no new bond was formed between the host material and fluorescent precursor during the process, with intermolecular forces being present between different molecules. Moreover, the thickness of the fluorescent film and quantum yield relation were evaluated. Finally, the hydrophobic nature, strong binding ability, and optical enhancement by PVB provide a powerful tool for fabricating a highly efficient fluorescent film with enhanced stability in an external environment based on its promising encapsulation properties. These efficient fluorescent films have a bright potential in colour conversion for next-generation display applications. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C30H42N4O2, has orthorhombic (Pbca) symmetry. This compound comprises a 4-amino-1,8-naphthalimide core with a 2,2,6,6-tetramethyl-4-piperidinyl substituent bonded to each nitrogen atom. The structure displays N--H· · ·O hydrogen bonding. The structure exhibits disorder of the main molecule. [ABSTRACT FROM AUTHOR]

Technological advancement leads researchers to develop multifunctional materials. Considering such trends, this study aimed to conjugate dual functionality in a single material to satisfy aesthetic and functional necessities. We investigated the potentiality of polysorbate 20 to perform as an effective ultraviolet absorber to develop UV-protective fabric. Coumarin derivative (Benzoxazolyl type) disperse dyes are well-known as fluorescent colors. On the other hand, luminescence materials are conspicuous and viable for fashion trends. Deliberate utilization of this inherent property of the dye and incorporation of polysorbate fulfilled the need for dual functionality. In addition, the knitted fabric structure enhanced wearing comfort as well. The effect of polysorbate consolidated the PET fabric as an excellent UV absorber, exhibiting an ultraviolet protection factor (UPF) of 53.71 and a blocking percentage of more than 95% for both UVA and UVB. Surface morphology was studied by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) with attenuated mode was used to investigate chemical modification. Moreover, X-ray diffraction (XRD) investigated the crystallography of the surface. Reflectance spectrophotometric analysis unveiled the color strength (K/S) of the dyed polyester fabrics. Finally, light fastness assessment revealed that the developed samples could resist a certain amount of photo fading under a controlled testing environment with the increment of ratings towards betterment. [ABSTRACT FROM AUTHOR]

• Characterization of fluorescent dye binding sites on antibodies. • Structure function analysis by mass spectrometry. • To have an inert tracer, minimal labeling is highly effective but not enough. • An inert tracer for determination of residence time distribution in chromatography. Fluorescently labeled antibodies are widely used to visualize the adsorption process in protein chromatography using confocal laser scanning microscopy (CLSM), but also as a tracer for determination of residence time distribution (RTD) in continuous chromatography. It is assumed that the labeled protein is inert and representative of the unlabeled antibody, ignoring the fact that labeling with a fluorescent dye can change the characteristics of the original molecule. It became evident that the fluorescently labeled antibody has a higher affinity toward protein A resins such as MabSelect Sure. This can be due to slight differences in hydrophobicity and net charge, which are caused by the addition of the fluorescent dye. However, this difference is eliminated when using high salt concentrations in the adsorption studies. In this work, the site occupancy of two labeled antibodies, MAb1 (IgG1 subclass) and MAb2 (IgG2 subclass) conjugated with the fluorescent dye Alexa Fluor™ 488 was elucidated by intact mass spectrometry (MS) and peptide mapping LC-MS/MS, employing a sequential cleavage with Endoproteinase Lys-C and trypsin and in parallel with chymotrypsin alone. It was shown that the main binding site for the dye was a specific lysine in the heavy chains of the MAb1 and MAb2 molecules, in positions 188 and 189 respectively. Other lysine residues distributed throughout the protein sequence were labeled to a lot lesser extent. The labeled antibody had a slightly different affinity to MabSelect Sure although its primary binding site (to Protein A) was not affected by labeling, despite the secondary region responsible for binding to the protein A was partly labeled. Overall, the fluorescent-labeled antibodies are a good compromise as an inert tracer in residence time distribution and chromatography studies because they are much cheaper than isotope-labeled antibodies; However, the differences between the labeled and unlabeled antibodies should be considered. [ABSTRACT FROM AUTHOR]

We explored the application of fluorescent dye doped Cholesteric Liquid Crystal (CLC) shells for anti-counterfeiting measures. These shells exhibit unique optical properties and, when infused with a fluorescent dye, produce a distinct fluorescent color upon exposure to UV light. We developed a microfluidic device using glass capillaries to generate uniform CLC shells. The shells were analyzed using a Polarizing Optical Microscope (POM) to study their defect structures. For anti-counterfeiting, QR code was encoded with CLC shells that were photopolymerized under ultraviolet light for enhanced durability. In daylight, the code reflects red and blue colors, but under UV light, it reveals the fluorescent dye color. This QR code can only be decrypted with UV illumination in both red and blue CLC shells. The color changes are easily visible to the naked eye, making this technique suitable for immediate verification. By utilizing this straightforward technique, security and chromic-based applications can be implemented with significantly increased cost-effectiveness and efficiency, surpassing the results of traditional approaches. • We built a microfluidic system employing glass capillaries to create monodispersed CLC shells. • Doping CLC shells with fluorescent dye enhances their applicability in security. • Encrypted QR codes reflect red and blue in daytime and release fluorescent dye under UV radiation, providing a dual-mode verification technique. • QR codes can only be decrypted under UV light, adding security to anti-counterfeiting methods. • CLC-based techniques are simpler, cost-effective, and efficient compared to traditional methods. [ABSTRACT FROM AUTHOR]

The four-cyclic condensed aromatic ketone 7H-benz[de]anthracene-7-one and its derivatives belong to the class of important anthraquinoid dyes, including laser and luminescent dyes. Current work is devoted to the synthesis of 3-cyanobenzanthrone and its evaluation of being a useful precursor for obtaining new 3-substituted derivatives with heterocyclic moieties, a handful of which have been synthesized up to now. The photophysical properties of the prepared compounds are investigated. The synthesized derivatives have pronounced fluorescence and are fluorescent "turn-off" probes for acidic environment. Therefore, these compounds can be used for pH sensing and as dyes in materials science and for visualization of biological structures. [ABSTRACT FROM AUTHOR]

Quantitative measurement of the degree of hepatic ischemia-reperfusion injury (IRI) is crucial for developing therapeutic strategies for its treatment. We hypothesized that clearance of fluorescent dye through bile metabolism may reflect the degree of hepatic IRI. In this study, we investigated sodium fluorescein clearance kinetics in blood and bile for quantifying the degree of hepatic IRI. Warm ischemia times (WITs) of 0, 30, or 60 min followed by 1 h or 4 h of reperfusion, were applied to the median and lateral lobes of the liver in Sprague-Dawley rats. Subsequently, 2 mg/kg of sodium fluorescein was injected intravenously, and blood and bile samples were collected over 60 min to measure fluorescence intensities. The bile-to-plasma fluorescence ratios demonstrated an inverse correlation with WIT and were distinctly lower in the 60-min WIT group than in the control or 30- min WIT groups. Bile-to-plasma fluorescence ratios displayed superior discriminability for short versus long WITs when measured 1 h after reperfusion versus 4 h. We conclude that the bile-to-blood ratio of fluorescence after sodium fluorescein injection has the potential to enable the quantification of hepatic IRI severity. [ABSTRACT FROM AUTHOR]

Although plastics have benefited our lives in terms of cost and convenience, the disposal of end-of-life plastics poses environmental problems, such as microplastics (MPs). Although the separation (e.g., filtration) and staining of MPs with fluorescent dye/solvent are generally accepted steps to observe MPs in an environmental matrix, in this study, an in situ selective fluorescent illumination of the MPs in water was attempted with the aid of surfactant. Nonpolar fluorescent dye in combination with surfactant affords nanometer-sized dye particles in water, which adsorb on MPs and penetrate the polymer matrix for effective staining and stable fluorescent behaviors. The effects of different staining parameters, including different dyes, surfactants, staining temperatures, staining times, dye/surfactant ratios, dye/MP ratios, and MP concentrations in aqueous solutions were investigated to better understand staining conditions. More interestingly, non-adsorbed free dye molecules in the staining solution were almost completely fluorescence-quenched by introducing the quenching agent, aniline, while the fluorescence intensity of the stained MP was maintained. By staining MPs with a dye/surfactant combination and subsequently quenching with aniline, in situ selective fluorescent illumination of the MPs in water was successfully achieved, which may eliminate the tedious separation/filtration procedure of MPs to accomplish the quick detection or monitoring of MPs. [ABSTRACT FROM AUTHOR]

We report a simple two-step method for the synthesis of a novel highly fluorescent benzothiophene-based dye comprising five fused rings and exhibiting a large Stokes shift (Δλ = 152 nm or Δν = 5482 cm–1 in ethanol). Structural features of the obtained compound allow easy functionalization of the carbon core and open new possibility for the development of a series of new classes of fluorescent dyes. [ABSTRACT FROM AUTHOR]

A water‐stable zirconium‐based metal–organic framework, MOF‐808, has been applied in selective adsorption and separation of the dyes (anionic fluorescein sodium [FS] and cationic rhodamine B [RhB]). Single‐component adsorption experiments indicate the superior adsorption of FS with a maximum adsorption capacity of 480.2 mg g−1, almost four times of the capacity for RhB. Further separation study shows that separation of these dyes can be achieved at a wide pH range of 3.5–8.5 and continuous separation is feasible in a simulated chromatographic column. Besides, this material can be well regenerated through acid washing method. Pore sieving effect is considered to be the key factor for the highly efficiency separation, and the host–guest interactions including H‐bond, π–π stacking, and coordination interactions are the main driven forces for the adsorption. Thus, this work demonstrates that MOF‐808 not only is a promising material for efficient separation of FS and RhB but also provides a new perspective for developing adsorbent with the help of distinct pore and chemical properties of MOFs. [ABSTRACT FROM AUTHOR]

Purpose of this research was to find the best blue-emitting fluorescent substance for plastic scintillator used for gamma radiation dosimetry. Scintillator should convert gamma radiation into blue light with high efficiency. Plastic scintillators with fixed concentration of various fluorescent additives, called wavelength shifters, absorbing ultraviolet light and emitting blue light were manufactured by radical bulk polymerization of styrene. Light output were measured and compared to the light output of commercial plastic scintillator. Performed measurements of charge Compton spectra confirmed usefulness of majority of researched substances as wavelength shifters in plastic scintillators with emission maximum at blue range of visible light. Plastic scintillation dosimeter may be constructed from manufactured polystyrene-based scintillators. Performance of synthesized scintillators is close to commercial polystyrene scintillators. [ABSTRACT FROM AUTHOR]

Lysosomes and lipid droplets (LDs), as two crucial sub-organelles within cells, play a pivotal role in maintaining the normal cellular functions. However, rational design and synthesis of fluorophores that selectively target specific organelles still pose a challenge. Herein, we developed a series of eight fluorescent dyes (LCA1-LCA4 and LCN1-LCN4) containing morpholine moiety, which effectively targeting lysosome and LDs within cells through rational regulation of substituents in the molecular structure. Among these compounds, compounds LCA1 / LCN1 containing triphenylamine group and LCA3 / LCN4 containing coumarin group exhibit specific targeting towards the LDs, whereas compound LCN2 containing carbazole group demonstrates targeted localization to lysosome. Moreover, these five compounds displayed the advantages of high cellular viability, excellent resistance to interference, pH insensitivity and the ability to enter cells without washing. Compounds LCN2 and LCA1 are capable of real-time monitoring the dynamic behavior of lysosome and LDs respectively, as well as the mitophagy (LCN2) or the number and diameter variations of LDs (LCA1). The results provide a potential candidate for specific lysosomes and LDs imaging. [Display omitted] • Eight fluorescent dyes containing morpholine moiety have been rationally regulated to target different organelles. • Compounds LCA1, LCA3 , LCN1 and LCN4 are capable of targeting LDs via wash-free procedure. • LCN2 with carbazole group could rapidly targeting lysosomes within 20 s without any washing step. • LCN2 enables real-time monitoring the dynamic process of lysosomes and mitophagy. • Compound LCA1 can be applied to tracking the dynamic behaviors and variation (number and diameter) of LDs. [ABSTRACT FROM AUTHOR]

Hollow organic molecular cocrystals comprised of 9‐methylanthracene‐1,2,4,5‐tetracyanobenzene (9MA‐TCNB) and naphthalene‐1,2,4,5‐tetracyanobenzene (NAPH‐TCNB) were fabricated using a surfactant‐mediated co‐reprecipitation method. The crystals exhibit a narrow size distribution that can be easily tuned by varying the concentration of surfactant and incubation temperature. The rectangular crystals possess symmetrical twinned cavities with an estimated storage volume on the order of 10−10 L. An aqueous dye solution can be incorporated into the cavities during crystal growth and stored inside for up to several hours, confirming the sealed nature of the hollow chambers. Our results demonstrate that it is possible to harness non‐classical crystal growth to fabricate organic molecular crystals with novel topologies. [ABSTRACT FROM AUTHOR]

Hollow organic molecular cocrystals comprised of 9‐methylanthracene‐1,2,4,5‐tetracyanobenzene (9MA‐TCNB) and naphthalene‐1,2,4,5‐tetracyanobenzene (NAPH‐TCNB) were fabricated using a surfactant‐mediated co‐reprecipitation method. The crystals exhibit a narrow size distribution that can be easily tuned by varying the concentration of surfactant and incubation temperature. The rectangular crystals possess symmetrical twinned cavities with an estimated storage volume on the order of 10−10 L. An aqueous dye solution can be incorporated into the cavities during crystal growth and stored inside for up to several hours, confirming the sealed nature of the hollow chambers. Our results demonstrate that it is possible to harness non‐classical crystal growth to fabricate organic molecular crystals with novel topologies. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) have numerous potential applications in the field of healthcare and diagnostics, and research into their biological functions is rapidly increasing. Mainly because of their small size and heterogeneity, there are significant challenges associated with their analysis and despite overt evidence of the potential of EVs in clinical diagnostic practice, guidelines for analytical procedures have not yet been properly established. Here, we present an overview of the main methods for studying the properties of EVs based on the principles of fluorescence. Setting aside the isolation, purification and physicochemical characterization strategies which answer questions about the size, surface charge and stability of EVs (reviewed elsewhere), we focus on available optical tools that enable the direct analysis of phenotype and mechanisms of interaction with tissues. In brief, the topics on which we elaborate range from the most popular approaches such as nanoparticle tracking analysis and flow cytometry, to less commonly used techniques such as fluorescence depolarization and microarrays as well as emerging areas such as fast fluorescence lifetime imaging microscopy (FLIM). We highlight that understanding the strengths and limitations of each method is essential for choosing the most appropriate combination of analytical tools. Finally, future directions of this rapidly developing area of medical diagnostics are discussed. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) have numerous potential applications in the field of healthcare and diagnostics, and research into their biological functions is rapidly increasing. Mainly because of their small size and heterogeneity, there are significant challenges associated with their analysis and despite overt evidence of the potential of EVs in clinical diagnostic practice, guidelines for analytical procedures have not yet been properly established. Here, we present an overview of the main methods for studying the properties of EVs based on the principles of fluorescence. Setting aside the isolation, purification and physicochemical characterization strategies which answer questions about the size, surface charge and stability of EVs (reviewed elsewhere), we focus on available optical tools that enable the direct analysis of phenotype and mechanisms of interaction with tissues. In brief, the topics on which we elaborate range from the most popular approaches such as nanoparticle tracking analysis and flow cytometry, to less commonly used techniques such as fluorescence depolarization and microarrays as well as emerging areas such as fast fluorescence lifetime imaging microscopy (FLIM). We highlight that understanding the strengths and limitations of each method is essential for choosing the most appropriate combination of analytical tools. Finally, future directions of this rapidly developing area of medical diagnostics are discussed. [ABSTRACT FROM AUTHOR]

Fluorescence of thioflavin T (ThT), a universal marker for amyloid fibril investigations, is shown to be highly dependent on fibrils' surface charge. This feature sheds new light on the relationship between ThT fluorescence and amyloid peptide fibrillation. Thioflavin T (ThT), a benzothiazole-based fluorophore, is a prominent dye widely employed for monitoring amyloid fibril assembly. Despite the near-universal presumption that ThT binds to β-sheet domains upon fibrillar surface via hydrophobic forces, the contribution of the positive charge of ThT to fibril binding and concomitant fluorescence enhancement have not been thoroughly assessed. Here we demonstrate a considerable interdependence between ThT fluorescence and electrostatic charges of peptide fibrils. Specifically, by analyzing both fibril-forming synthetic peptides and prominent natural fibrillar peptides, we demonstrate pronounced modulations of ThT fluorescence signal that were solely dependent upon electrostatic interactions between ThT and peptide surface. The results further attest to the fact that fibril ζ-potential rather than pH-dependent assembly of the fibrils constitute the primary factor affecting ThT binding and fluorescence. This study provides the first quantitative assessment of electrostatically driven ThT fluorescence upon adsorption to amyloid fibrils. [ABSTRACT FROM AUTHOR]

Background: Marking mosquitoes is vital for mark-release-recapture and many laboratory studies, but their small size precludes the use of methods that are available for larger animals such as unique identifier tags and radio devices. Fluorescent dust is the most commonly used method to distinguish released individuals from the wild population. Numerous colours and combinations can be used, however, dust sometimes affects longevity and behaviour so alternatives that do not have these effects would contribute substantially. Rhodamine B has previously been demonstrated to be useful for marking adult Aedes aegypti males when added to the sugar meal. Unlike dust, this also marked the seminal fluid making it possible to detect matings by marked males in the spermatheca of females. Here, marking of Anopheles gambiae sensu stricto with rhodamine B and uranine was performed to estimate their potential contribution. Methods: Two fluorescent markers, rhodamine B and uranine, were dissolved in sugar water and fed to adult An. gambiae. Concentrations that are useful for marking individuals and seminal fluid were determined. The effects on adult longevity, the durability of the marking and detection of the marker in mated females was determined. Male mating competitiveness was also evaluated. Results: Rhodamine B marking in adults is detectable for at least 3 weeks, however uranine marking declines with time and at low doses can be confused with auto-fluorescence. Both can be used for marking seminal fluid which can be detected in females mated by marked males, but, again, at low concentrations uranine-marking is more easily confused with the natural fluorescence of seminal fluid. Neither dye affected mating competitiveness. Conclusions: Both markers tested could be useful for field and laboratory studies. Their use has substantial potential to contribute to a greater understanding of the bio-ecology of this important malaria vector. Rhodamine B has the advantage that it appears to be permanent and is less easily confused with auto-fluorescence. The primary limitation of both methods is that sugar feeding is necessary for marking and adults must be held for at least 2 nights to ensure all individuals are marked whereas dusts provide immediate and thorough marking. [ABSTRACT FROM AUTHOR]

Photophysical properties of fluorescent dyes such as Safranin T, Acridine Orange, Pyronin B and Pyronin Y in SDS micelles were examined by using spectroscopic techniques. Firstly, spherical micelles in deionized water were prepared with Sodium Dodecyl Sulfate (SDS) surfactants and they were transformed into their layered structures (lamellar micelles) by the aid of NaCl (sodium chloride). SEM studies confirmed the transformation of SDS micelles from the spherical structures to the lamellar structures. Secondly, absorption and fluorescence characteristics of the dyes in deionized water and the SDS micelles aqueous solutions were characterized in the presence of various NaCl concentrations at above the critical micelle concentration (CMC). Moreover, the photophysical properties of the dyes in various media were discussed by fluorescence quantum yield and fluorescence lifetime data. The micellar structures called a mimetic membrane system changed the photophysical properties of the dyes compared to those in deionized water. [ABSTRACT FROM AUTHOR]

Organic anion‐transporting polypeptide 1A2 (OATP1A2), expressed in the human blood–brain barrier, promotes drug uptake from the blood and hence can be exploited for central nervous system‐targeted drug delivery. The thyroid transporter OATP1C1, expressed in the choroid plexus and in astrocytes, is also a potential pharmacological target. Based on their established pharmacological relevance, screening the drug interaction profile of OATP1A2 and OATP1C1 is highly desirable. However, drug interaction screens require suitable model systems and functional assays. In the current study, uptake of a set of cell‐impermeable fluorescent dyes was screened in HEK‐293 and A431 cell lines overexpressing OATP1A2 and OATP1C1. Based on the uptake of fluorescent dye substrates, a functional assay was developed, which was used to characterize OATP inhibitors/substrates. We identify Live/Dead Green (LDG), Live‐or‐Dye 488, and sulforhodamines 101, G, and B as novel fluorescent substrates of OATP1A2 and OATP1C1. We show that LDG uptake is proportional to OATP1A2/1C1 expression, allowing the isolation of cells expressing high transporter levels. Additionally, dye uptake can be used to characterize the drug interaction pattern of OATP1A2 and OATP1C1. We demonstrate that third‐generation P‐glycoprotein inhibitors elacridar, tariquidar, and zosuquidar inhibit OATP1A2 function. Increased toxicity of elacridar in OATP1A2‐expressing cells suggests that OATP1A2 may modulate the distribution of this compound. The fluorescence‐based assays developed in the current study are a good alternative of radioligand‐based tests and pave the way toward high‐throughput screens for OATP1A2/1C1 drug interaction studies. [ABSTRACT FROM AUTHOR]

OBJECTIVES Fluorescence imaging using indocyanine green (ICG) allows for the intraoperative mapping of the vascular supply of various tissue beds. Although generally safe and effective, rare adverse effects have been reported including anaphylactoid reactions. The current study retrospectively reviewed our experience the intraoperative administration of ICG to pediatric patients. METHODS The anesthetic records of patients who received ICG over a 2-year time period were retrospectively reviewed and demographic, surgical, and medication data retrieved. Objective intraoperative data before and after the administration of ICG were also recorded. These included heart rate, systolic and diastolic blood pressures, oxygen saturation, and peak inflating pressure. RESULTS The study cohort included 100 patients with a median age of 12 years (9.5 ± 7.4 years) and the median weight being 44.5 kg (45.9 ± 36.9 kg). ICG was administered intravenously to all patients. In all cases, 2.5 mg/mL ICG solution was used, with a median dose of 1.1 mL (1.79 ± 1.8 mL). Eight patients received more than 1 dose of ICG, with no adverse respiratory or hemodynamic effects related to its use. CONCLUSIONS ICG fluorescence is an important imaging modality that can be safely used as an intraoperative adjunct to various surgical procedures in the pediatric population. [ABSTRACT FROM AUTHOR]

Enantiostyly is a floral polymorphism consisting in the presence of two floral morphs that differ in the deflection of the style to the right or left in the populations. Monomorphic enantiostyly consists in plants showing both morphs within an individual and is thought to promote pollen transference between morphs, reduce levels of self-pollination and geitonogamy and avoid damage to floral parts during pollinator’s visit. In this study, we examined the function of this floral polymorphism in a group of plants with non-typical enantiostylous characteristics, the family Vochysiaceae. In particular, we evaluated how floral morphology (both sexual organ separation and the match between complementary sexual organs in the morphs) is related to pollen deposition on the pollinators’ body and to patterns of pollen flow among individuals. For this, we used floral morphometrics, insect captures and fluorescent powder dyes. We confirmed that monomorphic enantiostyly increased pollen transference between morphs compared to non-enantiostyly. Moreover, pollen flow occurred only between flowers of opposite morph. We also observed that pollen deposition on the insect’s body depended on their body shape rather than floral morphology. In fact, an intertegular distance slightly larger than the anther–stigma distance in the flowers increased pollen transference because anthers filaments and stigmas are flexible, which facilitated pollen brushing on insects’ body when approaching the flowers. Since the species are self-incompatible, we further discuss the role of mirror flowers in the reduction of geitonogamy and inbreeding depression. [ABSTRACT FROM AUTHOR]

In this study, three carbazole-coumarin hybrid dyes were successfully synthesized, and their UV-vis absorption spectra, fluorescence spectra, and structural properties were investigated. The results indicated that diethyl 12-hexyl-2,9-dioxo-9,12-dihydro-2H-dipyrano[2,3-b:3',2'-h]-carbazole-3,8-dicarboxylate showed a slight red shift of the maximum absorption wavelength, and its fluorescence intensity was above 4000 arb units, about 22 times higher than that of ethyl 10-hexyl-8-hydroxy-2-oxo-2,10-dihydropyrano[2,3-b]carbazole-3-carboxylate and ethyl 10-hexyl-8-(hexyloxy)-2-oxo-2,10-dihydropyrano[2,3-b]carbazole-3-carboxylate in CHCl3. The fluorescence intensity of the three compounds first increases and then decreases with the rise of concentration, and the maximum emission wavelength shows a slight red shift. The stability pH range of diethyl 12-hexyl-2,9-dioxo-9,12-dihydro-2H-dipyrano[2,3-b:3',2'-h]carbazole-3,8-dicarboxylate in THF was 2–10. [ABSTRACT FROM AUTHOR]

Key points: The large‐pore channel pannexin 1 (Panx1) is expressed in many cell types and can open upon different, yet not fully established, stimuli.Panx1 permeability is often inferred from channel permeability to fluorescent dyes, but it is currently unknown whether dye permeability translates to permeability to other molecules.Cell shrinkage and C‐terminal cleavage led to a Panx1 open‐state with increased permeability to atomic ions (current), but did not alter ethidium uptake.Panx1 inhibitors affected Panx1‐mediated ion conduction differently from ethidium permeability, and inhibitor efficiency towards a given molecule therefore cannot be extrapolated to its effects on the permeability of another.We conclude that ethidium permeability does not reflect equal permeation of other molecules and thus is no measure of general Panx1 activity. Pannexin 1 (Panx1) is a large‐pore membrane channel connecting the extracellular milieu with the cell interior. While several activation regimes activate Panx1 in a variety of cell types, the selective permeability of an open Panx1 channel remains unresolved: does a given activation paradigm increase Panx1's permeability towards all permeants equally and does fluorescent dye flux serve as a proxy for biological permeation through an open channel? To explore permeant‐selectivity of Panx1 activation and inhibition, we employed Panx1‐expressing Xenopus laevis oocytes and HEK293T cells. We report that different mechanisms of activation of Panx1 differentially affected ethidium and atomic ion permeation. Most notably, C‐terminal truncation or cell shrinkage elevated Panx1‐mediated ion conductance, but had no effect on ethidium permeability. In contrast, extracellular pH changes predominantly affected ethidium permeability but not ionic conductance. High [K+]o did not increase the flux of either of the two permeants. Once open, Panx1 demonstrated preference for anionic permeants, such as Cl−, lactate and glutamate, while not supporting osmotic water flow. Panx1 inhibitors displayed enhanced potency towards Panx1‐mediated currents compared to that of ethidium uptake. We conclude that activation or inhibition of Panx1 display permeant‐selectivity and that permeation of ethidium does not necessarily reflect an equal permeation of smaller biological molecules and atomic ions. Key points: The large‐pore channel pannexin 1 (Panx1) is expressed in many cell types and can open upon different, yet not fully established, stimuli.Panx1 permeability is often inferred from channel permeability to fluorescent dyes, but it is currently unknown whether dye permeability translates to permeability to other molecules.Cell shrinkage and C‐terminal cleavage led to a Panx1 open‐state with increased permeability to atomic ions (current), but did not alter ethidium uptake.Panx1 inhibitors affected Panx1‐mediated ion conduction differently from ethidium permeability, and inhibitor efficiency towards a given molecule therefore cannot be extrapolated to its effects on the permeability of another.We conclude that ethidium permeability does not reflect equal permeation of other molecules and thus is no measure of general Panx1 activity. [ABSTRACT FROM AUTHOR]

This study presents an automated, image-based cytometry method for determination of total counts and viability of yeast cells by using a newly synthesized DNA fluorescent dye PO-TEDM-1 and a new Easycounter YC instrument. The synthesized polycationic asymmetric monomethine cyanine dye PO-TEDM-1 penetrates only into dead cells. The new fluorescent dye has high nucleic acid sensitivity and rapid interaction kinetics. The optimal concentration of the fluorescent dye for staining dead cells was 1 µg mL−1. The Easycounter YC system was used to determine the total cell count and viability of Saccharomyces carlsbergensis. The actual viability measured using the proposed method significantly correlated with the theoretical viability (R2 of 0.9988). The optimal linear interval was from 1 × 105 to 1 × 107 cells mL−1. The coefficient of variation with Easycounter YC in the optimal range was 2.5–4%, whereas that of the manual hemocytometry method, in the same range was higher, 15–23%. We tested the procedure in a study of the total cell count and viability of yeast cells from the propagators in beer production as a function of the dilution. The proposed method can be used in assays involving simple cell counting and quality assurance in sample bioprocessing. [ABSTRACT FROM AUTHOR]

Synthesis and Properties of Blue Fluorescent Dyes Based on Diphenylamine by Introducing an Acetylene Linkage Group with Carbazole and 1,8-Naphthalimide Keywords: Acetylene linkage; Carbazole; Naphthalimide; Fluorescent dye; Blue-emitting Fluorescent dye B 2 b was synthesized using intermediate B D2 b (11.87 mmol, 5 g) and intermediate B C4 b (33.88 mmol, 8.36 g) via the method used to prepare fluorescent dye B 1 b . These results indicate that fluorescent dyes B 2 b and B 4 b , substituted by two acetylene groups, have relatively large steric hindrance, however, both substituents maintain planarity owing to the presence of the acetylene linkage, as shown in Figures and. [Extracted from the article]

The availability of light is one of the key driving factors for photosynthesis. Chlorophyll and accessory pigments absorb light at some of the wavelengths present in the solar spectrum. If all other requirements are available in abundance, introducing more light to the system at wavelengths that can be absorbed will increase the growth rate of microalgae and the final biomass achieved up to the level of photosaturation. Therefore, the effect of shifting the spectrum of light available such that the photons unutilized in photosynthesis are converted to those that can be utilised was investigated. Spectral shifts converting UV light to blue light and green light to red light were carried out using films produced with Coumarin and Solvent Orange respectively. Dunaliella salina (CCAP 19-30) was grown in an airlift photobioreactor (ALB) which was coated with the wavelength shifting films. Dunaliella final biomass in the ALB, as determined by the optical density, were shown to increase by 36.9% for UV to blue light conversion and by 18.8% for green to red light conversion when using a coated ALB compared with an uncoated one. [ABSTRACT FROM AUTHOR]

This study explores a new approach to achieve a whitening effect on polyester fabric by utilizing a ground form of raw OB-1 (OB-1-G) in combination with dispersing agents. The whitening process parameters, such as whitening temperature, OB-1-G mass, and whitening time were optimized using the L 16 orthogonal array-based Taguchi methodology. The signal-to-noise ratio was carried out through a larger-is-better approach to augment the parameter responses, specifically the whiteness. The results suggest that the degree of whiteness of polyester fabric is significantly affected by the whitening treatment temperature (P < 0.05), with a contribution percentage of 93.87%. A whiteness index of 94.12 was achieved for the polyester fabric treated at the optimized conditions. The fabric treated with OB-1-G at the optimized conditions was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The investigation also included the correlation between the length of time spent in washing and rubbing, and their efficacy in achieving whitening outcomes. The research demonstrated the effectiveness of OB-1-G nanopowder in combination with dispersing agents as a fluorescent optical brightener for the optical brightening of polyester fiber with potential use in the textile industry on a larger scale. [Display omitted] • A novel method of optical whitening of polyester fabric with nanosized OB-1. • Taguchi methodology was implemented to optimize the whitening parameters. • The temperature significantly influences the whiteness of polyester fabric. • Color fastness properties were adequately stable. [ABSTRACT FROM AUTHOR]

• Validity of fluorescence dyes in reflecting the biodistribution of PTX was evaluated. • PTX-Cy5.5 and mPEG-PLA-Cy5.5 were synthesized and formulated into dye-loaded NPs. • Cy5.5 and Cy5.5 conjugates loaded NPs could truly reflect the biodistribution of PTX. • DiR failed to exactly reflect biodistribution of PTX when solely encapsulated in NPs. Fluorescence imaging is widely used to determine biodistribution of drugs in mice. However, the dye distribution may not be able to exactly reflect the true distribution of drug molecules. We synthesized PTX-Cy5.5 and mPEG-PLA-Cy5.5, and then prepared dye-loaded nanoparticles (NPs) (Cy5.5, DiR, PTX-Cy5.5, and mPEG-PLA-Cy5.5), dye and PTX co-loaded NPs, and PTX-loaded NPs, respectively. The particle sizes of resulting NPs were between 42.7 nm and 68.8 nm, and Zeta potential was between -0.86 mV and -8.49 mV. The biodistribution of fluorescent NPs (dye-loaded NPs and dye and PTX co-loaded NPs) on Bel-7402 tumor-bearing mice was studied via in vivo fluorescence imaging assays, results of which suggested that Cy5.5 loaded NPs and Cy5.5 conjugates (PTX-Cy5.5 and mPEG-PLA-Cy5.5) formulated NPs can reflect the tissue distribution of PTX whether it was incorporated or not. However, DiR failed to reflect true tissue distribution of PTX unless it was co-loaded with PTX. Based on these results, a guidance for the selection of dyes in drug distribution investigations and disease-targeted treatment was presented. [ABSTRACT FROM AUTHOR]

• Probe 3 with 2,4-dinitrophenoxyl group was strongly fluorescent. • Sulfhydryl-specific cleavage reaction released the hydroxyl group. • BODIPY fluorophore 2 was weakly fluorescent. • Probe 3 was highly selective and sensitive to H 2 S. • Probe 3 could be used to detect HS− in HCT-116 and CT-26 cells. 1-(2-Hydroxyphenyl)ethanone as a starting material, BODIPY 3 bearing 2,4-dinitrophenyl (DNP) group was prepared in total 7% yield. Probe 3 was strongly fluorescent. Sulfhydryl-specific cleavage reaction released the hydroxyl group. Due to the electron transfer of the hydroxyl group in 2 to the BODIPY core, dye 2 was weakly fluorescent. Naked-eye and fluorescent turn-off probe 3 was highly selective and sensitive to H 2 S, and could be used to detect HS− in HCT-116 and CT-26 cells, indicating its potential application for studying the effect of HS− in biological system. [ABSTRACT FROM AUTHOR]

Abstract In this work, we firstly developed a new rapid detection method of nimesulide (Nim) based on the boron and nitrogen co-doped carbon dots (B,N-CDs) as the fluorescence probe. The B,N-CDs were prepared by a facile hydrothermal treatment using ammonium citrate and bis(pinacolato)diboron as precursors. The as-prepared B,N-CDs were mono-dispersed with an average diameter of 3.3 nm, and exhibited good stability and strong fluorescence emission with a high quantum yield of 68.89%. The fluorescence of B,N-CDs was obviously quenched with the addition of Nim. A good linear relationship between ln (F 0 /F) and the concentration of Nim was obtained in the range of 0–100 μM, and the limit of detection was 125 nM. Furthermore, the proposed analysis method was successfully applied for the detection of Nim in pharmaceutical samples and recoveries ranged from 94.60%–96.73%. More remarkably, it was further found that the as-prepared B,N-CDs displayed bright blue solid-state fluorescence, exhibiting potential application in invisible fluorescent ink for anti-counterfeiting and fluorescent dye. Graphical abstract B, N co-doped CDs with high quantum yield was firstly used as fluorescent probe to detect the nimesulide in the tablet. Moreover, B, N-CDs solid display strong blue fluorescence, which show potential application in invisible fluorescent ink and fluorescent dye. Unlabelled Image Highlights • B,N do-doped CDs was firstly employed as fluorescent probe for the detection of nimesulide. • As-prepared B,N-CDs exhibited good stability and high quantum yield of 68.89%. • The proposed fluorescent sensor has been successfully used to detect the content of Nim in the tablet. • B,N-CDs exhibited potential application in invisible fluorescent ink and fluorescent dye. [ABSTRACT FROM AUTHOR]

Abstract We realize a white light emission based on metal-organic frameworks (MOFs), which are loaded with red/yellow/green/blue (R/Y/G/B) primary-colour fluorescent dye molecules. The MOF⊃dye powders emitting red/green/blue light are synthesized via an activated adsorption reaction, whilst the MOF⊃dye powder emitting yellow light is prepared via an in-situ reaction. By grinding these R/Y/G/B MOF⊃dye powders and adjusting the mass proportions of each primary-colour component, a white light emission with a quasi-flat spectrum is obtained. Experimentally, under excitation with an ultraviolet light (at a wavelength of 365 nm), the emission peaks of the R/Y/G/B MOF⊃dye powders are located at 621.0 nm, 560.0 nm, 522.5 nm and 438.5 nm, respectively. When the mass proportions of R/Y/G/B components are 35.3%, 21.2%, 14.7% and 28.8%, the full-width at half-maximum bandwidth of the light emission is 251.5 nm (from 391.5 nm to 643.0 nm), and the 1-dB bandwidth is 201.5 nm. The measured Commission Internationale de L'Eclairage (CIE) coordinates are (0.319, 0.341). The flat and wide spectrum of this material makes it a promising candidate in applications such as lighting, display and visible-light communication systems. Highlights • A white light emission based on a mixture of R/Y/G/B MOF⊃dye powders is realized. • The R/G/B dye molecules are loaded into MOF via an activated adsorption reaction. • The Y-dye molecules are incorporated into MOF via an in-situ reaction. • The mixed MOF⊃dye composite shows a spectrally wide and flat white light emission. [ABSTRACT FROM AUTHOR]

New fluorescent dyes derivatized on a classical thiazole orange framework are able to show unexpectedly strong interaction signal and unusual binding selectivity with different structures of nucleic acid, particularly when bound with double-stranded DNA or G-quadruplex DNA. The present study reveals that these small binding ligands simply bearing an additional amino side group on its parent molecule of thiazole orange have almost no background fluorescence in solution. Conversely, they are able to produce an extremely strong yellow emission signal upon interaction with targeting nucleic acids in live cells. The induced fluorescence intensity was approximately 10–15 times stronger than that of thiazole orange. The dyes are therefore excellent fluorescent stains for bio-sensing and bio-imaging applications. It is particularly suitable for fluorescence microscopy experiments requiring very low working concentration (0.25 μM or less) targeting nucleic acids. This was demonstrated using pu27 G-quadruplex DNA, which has a low limit of detection (LOD = 3–4 nM) while thiazole orange was much higher (LOD = 48.7 nM) under the same conditions. In addition, it was found that structural modification on the quinolinium scaffold of thiazole orange was less effective than modification on the benzothiazole moiety. The findings of the present study provide important information for structural advancement of small molecules based on the widely used thiazole orange skeleton, resulting in analogues that are able to achieve higher sensitivity and selectivity for targeting at a specific class of nucleic acids. Computational docking studies were also conducted to illustrate the interaction behaviors of the dyes with different DNA structures. [ABSTRACT FROM AUTHOR]

On base of the good optical properties of coumarin and fluorescein, we designed and synthesized two coumarin/fluorescein-fused fluorescent dyes ( CF dyes), which enlarged the emission wavelength and increased the Stokes shift of fluorescein moiety. The corresponding optical properties of CF dyes were investigated in detail. CF dyes could easily introduce other groups to design different functional molecules. CF dyes also exhibited rapid and sensitive responses to pH values in the range of 4.0–7.4 through the characterization of absorption and fluorescence spectra in buffer solution. More importantly, CF ethyl ester dye ( CFE dye) not only showed good cell membrane permeability and low cytotoxicity, but also had the ability to rapidly monitor mitochondrial pH changes in living cells. [ABSTRACT FROM AUTHOR]