A versatile fluorescent probe for the ratiometric detection of hydrazine (N2H4) in water, soil, plant, and food samples.

Hydrazine (N2H4) is a crucial chemical raw material extensively utilized in chemical production. However, due to its volatility, water solubility, and high toxicity, both the gaseous form and aqueous solution of N2H4 pose significant environmental risks by causing severe pollution that can adversely impact plants, microorganisms, and human health. Therefore, accurate detection of N2H4 in the environment is imperative for safeguarding public health. In this study, we synthesized a ratiometric fluorescent probe (BCaz-Cy2) based on Carbazole and Hemicyanine groups. This probe exhibits simple synthesis procedure, rapid response time, high sensitivity and selectivity as well as remarkable detection signals. It enables effective detection of N2H4 in various matrices such as water, food, soil and plant samples thereby significantly expanding the scope of applications for N2H4 probes.

A ratiometric fluorescent probe for selective detection of hypochlorite (ClO-) and gallium (III) (Ga3+) ions in environmental and food samples.

Hypochlorite (ClO-) and gallium (Ⅲ) ions (Ga3+) have extensive applications in various human industries and daily activities. However, their inherent toxicity poses significant risks to environmental preservation and human well-being. Hence, the development of reliable and handy detection tools for ClO- and Ga3+ in the environment and food is crucial. In this study, a ratiometric fluorescent probe was prepared based on benzothiazolaldehyde and pyridine-2-carboxylic acid hydrazide, which exhibited exceptional performance characteristics for the selective detection of ClO- and Ga3+. These features include high specificity, low detection limits (0.28 µM for ClO-, 0.13 µM for Ga3+), mild pH conditions (pH 4-11 for ClO-, pH 6-11 for Ga3+), fast response time (within 30 s), as well as versatile applicability across different matrices such as water, soil, food, and plant samples. Additionally, this probe can be used with a smartphone color recognition app. The probe offers a convenient and effective tool for the detection of ClO- and Ga3+, demonstrating its potential application value in environmental monitoring and food safety.

Recent Advances in Organic Small-Molecule Fluorescent Probes for the Detection of Zinc Ions (Zn2+).

Zinc(II) ions (Zn2g) play crucial roles in the growth, propagation, and metabolism of animals, plants, and humans. Abnormal concentrations of Zn2+ in the environment and living organisms pose potential risks to environmental protection and human health. Therefore, it is imperative to develop rapid, reliable and in-situ detection methods for Zn2+ in both environmental and biological contexts. Furthermore, effective analytical methods are required for diagnosing diseases and understanding physiological metabolic mechanisms associated with Zn2+ concentration levels. Organic small-molecule fluorescent probes offer advantages such as fast, reliable, convenient, non-destructive detection capabilities and have significant application potential in Zn2+ detection and bioimaging; thus garnering extensive attention. Over the past two years alone, various organic small-molecule probes for Zn2+ based on different detection mechanisms and fluorophores have been rapidly developed. However, these probes still exhibit several limitations that need further resolution. In light of this context, we provide a comprehensive summary of the detection mechanisms, performance characteristics, and application scope of Zn2+ fluorescence probes since year 2022 while highlighting their advantages. We also propose solutions to address existing issues with these probes and outline future directions for their advancement. This review aims to serve as a valuable reference source offering insights into the development of advanced organic small-molecule-based fluorescence probes specifically designed for detecting Zn2+.

Recent Advances in Organic Small-Molecule Fluorescent Probes Based on Dicyanoisophorone Derivatives.

Fluorescent probe technology holds great promise in the fields of environmental monitoring and clinical diagnosis due to its inherent advantages, including easy operation, reliable detection signals, fast analysis speed, and in situ imaging capabilities. In recent years, a wide range of fluorescent probes based on diverse fluorophores have been developed for the analysis and detection of various analytes, yielding significant achievement. Among these fluorophores, the dicyanoisophorone-based fluorophores have garnered significant attention. Dicyanoisoporone exhibits minimal fluorescence, yet possesses a robust electron-withdrawing capability, rendering it suitable for constructing of D-π-A structured fluorophores. Leveraging the intramolecular charge transfer (ICT) effect, such fluorophores exhibit near-infrared (NIR) fluorescence emission with a large Stokes shift, thereby offering remarkable advantages in the design and development of NIR fluorescence probes. This review article primarily focus on small-molecule dicyanoisoporone-based probes from the past two years, elucidating their design strategies, detection performances, and applications. Additionally, we summarize current challenges while predicting future directions to provide valuable references for developing novel and advanced fluorescence probes based on dicyanoisoporone derivatives.

A Halloysite Nanotubes-based Probe for Efficient Fluorescence Detection and Adsorption Removal of Pb2+ in Water.

The detection and removal of Pb2+ is of utmost importance for environmental protection and human health due to its toxicity, persistent pollution, and bioaccumulation effects. To address the limitations associated with organic small molecule-based fluorescence probes such as poor water solubility and single functionality in detecting Pb2+, a fluorescence probe based on halloysite nanotubes was developed. This probe not only enables specific, rapid, and reliable detection of Pb2+ but also facilitates efficient removal of it from water. The development of this bifunctional fluorescent probe provides a valuable insight for designing more advanced probes targeting heavy metal ions.

Analysis of HLA Profiles in 390 Uveitis Cases: Insights into Clinical Presentations.

Objective: This study aimed to explain the associations between different types of uveitis and human leukocyte antigen (HLA)-B27, HLA-DR4, and HLA-DRw53. Methods: A retrospective analysis of 390 uveitis cases was conducted among inpatients and outpatients diagnosed at Weifang Eye Hospital from 2013 to 2016. All 390 patients underwent HLA-B27 examination, and an additional 40 patients underwent examination for HLA-DR4 and HLA-DRw53. Gender, age, corrected visual acuity (CVA), and recurrence frequency were statistically analyzed based on the onset site and etiology classification. Results: Among the 390 enrolled patients, 206 were male, and 183 were female, with ages ranging from 6 to 87 years (mean: 44.2). The disease onset was classified into anterior uveitis (AU), panuveitis (panU), posterior uveitis (PU), and intermediate uveitis in 180, 112, 88, and 10 cases, respectively. HLA-B27 was positive in 94 cases (53 males and 41 females), yielding a positive rate of 24.1%. In AU patients, 80 (44.4%) tested positive for HLA-B27, while 8 (7.1%) panU patients and 6 PU patients (6.8%) were HLA-B27 positive; none of the intermediate uveitis (IU) patients exhibited HLA-B27 positivity. HLA-B27, HLA-DR4, and HLA-DRw53 examinations were performed on 40 patients with binocular uveitis, resulting in 2 HLA-B27 positive cases, 15 HLA-DR4 positive cases, and 20 HLA-DRw53 positive cases, with positive rates of 5%, 37.5%, and 50%, respectively. Among 25 Vogt Koyanagi-Harada (VKH) cases, 1 tested positive for HLA-B27, 22 were positive for HLA-DR4, and 24 were positive for HLA-DRw53, with positive rates of 4%, 88%, and 96%, respectively. No positive HLA-B27, HLA-DR4, or HLA-DRw53 cases were found among the 10 cases of Behcet's disease (BD). Conclusions: Human leukocyte antigens (HLAs) play a significant role in the mechanism of uveitis. HLA-B27 exhibits high diagnostic value in acute AU, while HLA-DR4 and HLA-DRw53 are crucial for diagnosing binocular uveitis, particularly Vogt Koyanagi-Harada (VKH) syndrome. Further investigation is warranted to explore the relationship between HLA-DR4, HLA-DRw53, and uveitis.

A Dicyanoisoflurone-based Near-infrared Fluorescence Probe for Highly Sensitive Detection of Hg2.

Due to its high toxicity, long durability, easy absorption by aquatic organisms, and significant bioaccumulation, Hg2+ has caused substantial environmental damage and posed serious threats to human health. Therefore, effective detection of Hg2+ is of utmost importance. In this study, a turn-on fluorescent probe based on dicyanoisoflurone was developed for the detection of Hg2+. The probe exhibited near-infrared fluorescence signal at 660 nm upon excitation by 440 nm UV light in a mixture of CH3CN and HEPES buffer (4:1, v/v, 10 mM, pH = 7.5), with selective binding to Hg2+ in a molar ratio of 1:1. This binding event was accompanied by a visible color change from light yellow to orange. By utilizing the enhanced fluorescence signal change, this probe enables highly sensitive analysis and detection of Hg2+ with excellent selectivity (association constant = 1.63 × 104 M- 1), large Stokes shift (220 nm), high sensitivity (detection limit as low as 5.6 nM), short reaction time (30 s), and a physiological pH range of 7.5-9.5. The probe was successfully employed for detecting of Hg2+ in real water and living cells.

Molecular Engineering to Achieve AIE-active Fluorophore with Near-infrared (NIR) Emission and Temperature-sensitive Property.

Near-infrared organic small molecule luminescent materials have the advantages of easy modification, high quantum efficiency, good biological affinity, and color adjustability; thus, have promising application prospects in the fields of photoelectric devices, sensitive detection, photodynamic therapy, and biomedical imaging. However, traditional organic luminescent molecules have the problems of short emission wavelength, aggregation-causing emission quenching, and low quantum yield. Herein, we successfully synthesized four D-π-A-D light-emitting molecules based on electron-withdrawing malonitrile group and different electron-donating arylamine groups. These compounds showed satisfactory solvatochromism, aggregation-induced emission, red and near-infrared fluorescence, high photoluminescence quantum efficiency and temperature response properties. This successful example of molecular engineering provides a valuable reference for the development of advanced NIR materials with AIE and temperature-sensitive properties.

A dual-functional fluorescent probe based on kaolin nanosheets for the detection and separation of aluminum ions.

Aluminum ions (Al3+) are closely related to environmental protection and human health, thus the detection and separation of Al3+ is of great significance. In this study, a dual-functional fluorescent probe for the detection and separation of Al3+ was successfully developed by grafting fluorophore onto kaolin nanosheets. The probe has the characteristics of good dispersion without the involvement of organic solvents, excellent specificity, the low limit of detection (0.55 µM), and fast response time (10 min). And the recovery rates of Al3+ using this probe are in the range from 93.0% to 101.8%, and the corresponding relative standard deviations are in the range from 3.5% to 5.8%. Besides, it also can remove Al3+ in aqueous solution through adsorption, and the removal rates is in the range from 95.1% to 99.3% when the concentration of the probe is 0.4 mg/mL. The probe combines detection and separation functions, overcomes the defect that single-function materials can only be used for detection or separation, which has important significance and good application value.

A dicyanisophorone-based probe for dual sensing Zn2+ and Cd2+ by near-infrared fluorescence.

Zinc ions (Zn2+) and cadmium ions (Cd2+) are widely present in our production and life, which are closely related to human health and environmental protection. Hence, it is essential to detect their concentrations. Herein, we developed a convenient and reliable small-molecule fluorescent probe based on Schiff base of dicyanisophorone and 2-hydrazinopyridine. This probe can be able to selectively detect Zn2+ and Cd2+, showing the advantages of near-infrared emission (the maximum emission wavelength: 668 nm), good selectivity, high sensitivity (the detection limits: 0.21 µM and 0.31 µM, respectively) and rapid response (15 s). It has excellent potential for rapid testing and visual tracking of Zn2+ and Cd2+ in aqueous solution and living cells.

A Critical Review on Organic Small Fluorescent Probes for Monitoring Carbon Monoxide in Biology.

Endogenous carbon monoxide (CO) is an important intracellular gas messenger that is intimately involved in many physiological and pathological processes. The abnormal concentration of CO in living organisms can cause many diseases. Therefore, it is of great significance to monitor CO in biological samples. Fluorescent probe technology provides an effective and convenient method for CO monitoring, with the advantages of high selectivity and sensitivity, fast response time and in situ fluorescence imaging in biological tissues, which is favored by the majority of researchers. In this paper, the research progress of CO fluorescent probes since 2018 is reviewed, and the design, detection mechanism and biological application of the related fluorescent probes are summarized. And the relationship between the structure and performance of the probes is discussed. Furthermore, the development trend and application prospect of CO fluorescent probes are prospected.

A near-infrared Fluorescent Probe Based on Dicyanisophorone for the Detection of Zinc Ions (Zn2+) in Water and Living Cells.

As one of the important metal ions, zinc ions (Zn2+) are widely involved in various physiological and pathological processes, and play fundamental roles in neurotransmission, cell metabolism and apoptosis. However, the convenient monitor of Zn2+ in environmental and biological samples remains challenging. In this study, a small molecule dicyanoisophorone-based schiff base incorporating with o-phenylenediamine was synthesized. It can rapidly combine with Zn2+ to emit significant near-infrared fluorescence (maximum emission wavelength: 660 nm), so it can be used as a probe to quantitatively detect Zn2+ in the range of 0-10 µM, with a detection limit as low as 4.8 nM, showing the probe has high sensitivity for Zn2+. And the probe has a fast response time to Zn2+ (less than 30 s) and a large Stoke-shift (179 nm). In addition, the high recovery rates in practical water samples, and the clear fluorescent images in living A549 cells were obtained, which are of great significance for the detection of Zn2+ in the environment and biosystem. Due to its simple operation, good selectivity and anti-interference ability, short detection time and high sensitivity, this probe has great application potential as a fast detection tool for Zn2+ in environmental water and biological samples.

Two near-infrared fluorescent probes based on dicyanoisfluorone for rapid monitoring of Zn2+and Pb2.

Zinc (Zn2+) and lead (Pb2+) ions in the environment have important effects on human health and environmental safety. Therefore, it is necessary to effectively detect them by a convenient and reliable analysis method. In this study, two near-infrared fluorescent probes for the fast determination of Zn2+and Pb2+were synthesized by a simple Schiff base reaction between the dicyanoisophorone skeleton and carbohydrazide derivatives. Among them, the probe with the thiophene-2-carbohydrazide group showed a selective fluorescence response to Zn2+and Pb2+with a maximum emission wavelength of 670 nm. And the detection limits of the probe for Zn2+and Pb2+were 1.59 nM and 1.65 nM, respectively. In contrast the probe modified by the furan-2-carbohydrazide group achieved quantitative detection of Zn2+, with a detection limit of 2.7 nM. These results were attributed to the fact that the probes bind to Zn2+and Pb2+in stoichiometric ratios of 1:1, blocking the intramolecular PET effect. Furthermore, these two probes can be recycled through the action of EDTA and have been successfully used to detect Zn2+and Pb2+in real water samples.

A near infrared fluorescent probe for detection and bioimaging of zinc ions and hypochlorous acid.

It is of great significance to monitor zinc ions (Zn2+) and hypochlorous acid (HClO) conveniently in disease diagnosis and environmental protection. Herein, we successfully prepared a near-infrared fluorescent probe based on dicyanoisophorone derivative and methyl hydrazate by Schiff base reaction for effective detection of Zn2+ and HClO. After binding with Zn2+ at a molar ratio of 1:1, the fluorescence intensity (λex = 482 nm, λem = 653 nm) of the probe was significantly enhanced, thus achieving quantitative detection and optical cell imaging of Zn2+. The complexation constant (K) of the probe with Zn2+ was 2.34 × 104 M-1. The response time of the probe for Zn2+ was less than 20 s and the detection limit was 15.3 nM. Moreover, this probe also showed a specific response to HClO. After interacting with HClO, the fluorescence intensity of the probe was increased significantly with a red shift of the emission wavelength from 670 nm to 705 nm (λex = 550 nm). The response time and the detection limit of probe for HClO were 4 min and 1.39 µM, respectively. The probe was successfully applied for visual bioimaging of Zn2+ and HClO inside living cells. The recoveries of Zn2+ and HClO using the probe in actual water samples were satisfactory.

A photochromic salicylaldehyde hydrazone derivative based on CN isomerization and ESIPT mechanisms and its detection of Al3+ in aqueous solution.

A simple photochromic Schiff base was successfully prepared by the condensation of salicylaldehyde and benzoyl hydrazine. This compound has reversible photochromic properties based on isomerization and ESIPT mechanisms. In organic solvents, after irradiation with 365 nm UV light for 2 min, the absorption peak at 367 nm of the compound showed a significant decrease, while a double absorption peak appeared at 418 nm and 438 nm, accompanied by a significant change of the solution color from colorless to yellow. The compound can also complex with Al3+ at the molar ratio of 2:1 in the water solution (acetonitrile/water, v/v, 1:99), resulting in significantly enhanced fluorescence of the compound, so as to achieve fluorescence detection of Al3+ in living cells and water samples.

Polyethyleneimine-Functionalized Carbon Nanotubes Enabling Potent Antimycotic Activity of Lyticase.

In this work, the positively-charged polymer polyethyleneimine was used to functionalize carbon nanotubes and activated carbon to load antimycotic enzyme lyticase. Interestingly, polyethyleneimine played a dual role functionalizing carbon materials to synergistically enhance antimycotic activity of loaded lyticase as well as exhibiting its own apparent antimycotic activity, where the enhanced enzymatic activity of loaded lyticase on functionalized carbon nanotubes was more than 2.8 times as high as the activity of free enzyme in solution. The actual activity of loaded lyticase on functionalized carbon nanotubes was applied with Penicillium janthinellum, exhibiting much faster digesting lysis of the bacteria in comparison with free lyticase. The synergistic and potent antimycotic activities from combined action of antimycotic lyticase and polyethyleneimine on carbon nanotubes provides a new antimycotic protection for medicine, food industry, and other biochemical processes.

Recent Progress in the Development of Fluorescent Probes for the Detection of Hydrazine (N2H4).

ABSTACTWith the widespread use of N2H4, it brings potential risk to human health and environmental safety because of its diverse toxicological functions. In order to determine N2H4 effectively in both environment and living systems, all kinds of fluorescence probes have been prepared for the specific response of N2H4 based on various mechanisms and different acceptor group for N2H4. This paper provides a review to bring more inspirations for the development of the fluorescent probes for N2H4.

Blocking the formation of bromate in γ-Fe-Ti-Al2O3 catalytic ozonation of ibuprofen in bromide-containing water.

Iron and titanium doped γ-Al2O3 (γ-Fe-Ti-Al2O3) mesoporous catalysts were synthesized by evaporation-induced self-assembly using glucose as template, and applied to ozonation of ibuprofen in bromide-containing water. X-ray diffraction (XRD), nitrogen adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) results showed that iron and titanium successfully doped into the skeleton of γ-Al2O3, uniform distribution, maintain the ordered mesoporous structure of γ-Al2O3, with larger specific surface area. The valence of titanium coexists with Ti4+ and Ti3+, and the valence of iron was Fe3+. Infrared spectra of chemisorbed pyridine (Py-FTIR) results showed that the doped titanium and iron into the framework position of γ-Al2O3 altered the surface acidity of the alumina surface, especially increasing the medium Lewis acid sites, which was conducive to the effective decomposition of ozone into active oxygen species. The γ-Fe-Ti-Al2O3 catalyst (Al/Fe = 25, Al/Ti = 75) enhanced the removal rate of ibuprofen in ozonation of bromide-containing water, and effectively blocked the formation of bromate. After the reaction of 60 min, the removal rate of TOC was increased from 54% of γ-Al2O3/O3 to 86% with γ-Fe-Ti-Al2O3/O3, while the ozonation alone was only 13%. Electron Paramagnetic Resonance (EPR) spectra showed that hydroxyl and superoxide radicals were reactive oxygen species, which was beneficial to the mineralization of organic matter. The capture experiment of Fe2+ ion confirmed that the electronic cycle of Fe2+ ion and Fe3+ ion was beneficial to block the formation of bromated. The addition of ibuprofen and humic acid can enhance the reduction of Fe3+ in the catalytic ozonation of γ-Fe-Ti-Al2O3, which further strengthened the blocking of bromate formation.

A cationic fluorescent probe for highly selective detection of sodium dodecyl sulfate (SDS) by electrostatic and hydrophobic self-assembly.

Sodium dodecyl sulfate (SDS) has a wide range of applications in the chemical industry due to its excellent characteristics including good emulsification, foaming, water solubility and stability, easy synthesis and low price. However, it is a kind of anionic surfactant which is slightly toxic to the human body, and use of a large amount will cause potential pollution of the environment. Therefore, the development of a simple method to realize the monitoring of SDS in the environment is of great significance. Herein, a cationic fluorescent probe was prepared by the condensation reaction between 4-di-p-tolylamino-benzaldehyde and 3-ethylbenzothiazolium iodide. It can be used for the quantitative determination of SDS in the range of 5-50 µM showing red fluorescence and high selectivity by forming banded assemblies. This work provides an effective tool based on a new strategy for the detection of SDS.