Facile and green synthesis of chlorophyll-derived multi-color fluorescent carbonized polymer dots and their use for sensitive detection of hemin.

Due to the very important role in physiological process, a simple and sensitive hemin detection method is necessarily required. Biomass-based carbonized polymer dots (CPDs) have been widely studied especially as fluorescence probe owing to the advantages of low toxicity and the variety of fluorescence color, yet there are still challenges in developing their multi-color emission property from the same raw materials. In this work, red, white and blue emissive CPDs derived from chlorophyll have been synthesized via hydrothermal method. Then white-emitted CPDs (white-CPDs) with the Commission International d'Eclairage (CIE) coordinates at (0.34, 0.32) were used to develop a fluorescence quenched sensing system for hemin determination. There is a good linear relationship between (F0-F)/F0 and concentration of hemin in the range of 0.1-0.95 µM with a detection limit of 0.043 µM, and the quenching mechanism was considered to be caused by inner filter effect (IFE). Moreover, it has been successfully used for hemin detection in serum and also for visual determination, which indicating great potential in applications of disease diagnoses and trace identification.

Photocatalytic Degradation of Acetaminophen in Aqueous Environments: A Mini Review.

Over the past few decades, acetaminophen (ACT), a typical nonsteroidal anti-inflammatory drug (NSAID), has gained global usage, positioning itself as one of the most extensively consumed medications. However, the incomplete metabolism of ACT leads to a substantial discharge into the environment, classifying it as an environmental contaminant with detrimental effects on non-target organisms. Various wastewater treatment technologies have been developed for ACT removal to mitigate its potential environmental risk. Particularly, photocatalytic technology has garnered significant attention as it exhibits high efficiency in oxidizing and degrading a wide range of organic pollutants. This comprehensive review aims to systematically examine and discuss the application of photocatalytic technology for the removal of ACT from aqueous environments. Additionally, the study provides a detailed overview of the limitations associated with the photocatalytic degradation of ACT in practical applications, along with effective strategies to address these challenges.

Composition Engineering Growth of Cs3Bi2I9 Single Crystals with Low Defect Density for X-ray Detectors.

Cs3Bi2I9 (CBI) single crystal (SC) is a promising material for a higher-performance direct X-ray detector. However, the composition of CBI SC prepared by the solution method usually deviates from the ideal stoichiometric ratio, which limits the detector performance. In this paper, based on the finite element analysis method, the growth model of the top-seed solution method has been established, and then the influence of precursor ratio, temperature field, and other parameters on the composition of CBI SC has been simulated. The simulation results were used to guide the growth of the CBI SCs. Finally, a high-quality CBI SC with a stoichiometric ratio of Cs/Bi/I = 2.87:2:8.95 has been successfully grown, and the defect density is as low as 1.03 × 109 cm-3, the carrier lifetime is as high as 16.7 ns, and the resistivity is as high as 1.44 × 1012 Ω·cm. The X-ray detector based on this SC has a sensitivity of 29386.2 µC·Gyair-1 cm-2 at an electric field of 40 V·mm-1, and a low detection limit of 0.36 nGyair·s-1, creating a record for the all-inorganic perovskite materials.

A review of spectroscopic probes constructed from aptamer-binding gold/silver nanoparticles or their dimers in environmental pollutants' detection.

The issue of environmental pollutant residues has gained wide public attention all along. Therefore, it is necessary to develop simple, rapid, economical, portable, and sensitive detection techniques, which have become the focus of research in the pollutants detection field. Spectroscopy is one of the most convenient, simple, rapid, and intuitive analytical tools that can provide accurate information, such as ultraviolet spectroscopy, fluorescence spectroscopy, Raman spectroscopy, plasmon resonance spectroscopy, etc. Gold nanoparticles, silver nanoparticles, and their dimers with unique optical properties are commonly used in the construction of spectroscopic probes. As a class of oligonucleotides that can recognize specific target molecules, aptamers also have a strong ability to recognize small-molecule pollutants. The application of aptamer-binding metal nanoparticles in biosensing detection presents significant advantages for instance high sensitivity, good selectivity, and rapid analysis. And many spectroscopic probes constructed by aptamer-binding gold nanoparticles, silver nanoparticles, or their dimers have been successfully demonstrated for detecting pollutants. This review summarizes the progress, advantages, and disadvantages of aptamer sensing techniques constructed by visual colorimetric, fluorescence, Raman, and plasmon resonance spectroscopic probes combining gold/silver nanoparticles or their dimers in the field of pollutants detection, and discusses the prospects and challenges for their future.

Partially fluorinated nanoemulsions for 19F MRI-fluorescence dual imaging cell tracking.

Fluorine-19 magnetic resonance imaging (19F MRI) has been a technology of choice for in vivo cell tracking, in which perfluorocarbons (PFCs) nanoemulsions are the most used 19F MRI agents. However, the peculiar physicochemical properties of PFCs may lead to poor cell uptake and misleading cell tracking results. Herein, we employed partially fluorinated aromatic agents to formulate paramagnetic nanoemulsions as novel 19F MRI-fluorescence (FL) dual imaging agents for cell tracking. With the intramolecular π-π interaction, low density and fluorine content, the partially fluorinated agents enable considerable solubilities of functional agents and short relaxation times, which facilitates convenient preparation of stable, biocompatible, and multifunctional nanoemulsions with high 19F MRI sensitivity. Replacing PFCs in 19F MRI nanoemulsions with readily available partially fluorinated aromatic agents may address many issues associated with PFCs and provide a novel strategy for high-performance 19F MRI agents of broad biomedical applications.

Synthesis of trifluoromethylated aza-BODIPYs as fluorescence-19F MRI dual imaging and photodynamic agents.

Dual-imaging agents with highly sensitive fluorescence (FL) imaging and highly selective fluorine-19 magnetic resonance imaging (19F MRI) are valuable for biomedical research. At the same time, photosensitizers with a high reactive oxygen species (ROS) generating capability are crucial for photodynamic therapy (PDT) of cancer. Herein, a series of tetra-trifluoromethylated aza-boron dipyrromethenes (aza-BODIPYs) were conveniently synthesized from readily available building blocks and their physicochemical properties, including ultraviolet-visible (UV-Vis) absorption, FL emission, photothermal efficacy, ROS generating efficacy, and 19F MRI sensitivity, were systematically investigated. An aza-BODIPY with 12 symmetrical fluorines was identified as a potent FL-19F MRI dual-imaging traceable photodynamic agent. It was found that the selective introduction of trifluoromethyl (CF3) groups into aza-BODIPYs may considerably improve their UV absorption, FL emission, photothermal efficacy, and ROS generating properties, which lays the foundation for the rational design of trifluoromethylated aza-BODIPYs in biomedical applications.

Hydrofluorocarbon nanoparticles for 19F MRI-fluorescence dual imaging and chemo-photodynamic therapy.

The synergistic chemotherapy and photodynamic therapy (PDT) may significantly improve the cancer therapeutic efficacy, in which fluorinated nanoemulsions are highly advantageous for their ability to deliver oxygen to hypoxic tumors and provide fluorine-19 magnetic resonance imaging (19F MRI). The low solubility of chemotherapy drugs and photosensitizers in current perfluorocarbon (PFC)-based 19F MRI agents usually leads to complicated formulations or chemical modifications and low nanoemulsion stability and performance. Herein, we employ readily available partially fluorinated ethyl 2-(3,5-bis(trifluoromethyl)phenyl)acetate as the 19F MRI agent and the solvent to dissolve the cancer stem cell inhibitor salinomycin and the photosensitizer ICG for the convenient preparation of 19F MRI-fluorescence dual imaging and synergistic chemotherapy, photothermal and photodynamic therapy nanoemulsions. The chemotherapy drug salinomycin has a high solubility in the partially fluorinated reagent, facilitating its high loading and efficient delivery. Paramagnetic iron(III) (Fe3+) is incorporated into the nanoemulsion through the dissolved chelator to significantly improve the 19F MRI sensitivity. Furthermore, the dissolved fluorinated 2-pyridone enables the efficient capture and sustained release of singlet oxygen in the dark for high PDT efficacy. The multifunctional nanoemulsions show sensitive 19F MRI and fluorescence dual imaging capability and high synergistic chemotherapy, photothermal and photodynamic therapy efficacy in cancer cells, which may be valuable oxygen delivery, sustained ROS generating and release, dual imaging and multimodal therapy agents for hypoxic tumors. This study provided a convenient co-solubilization strategy for the rapid construction of multifunctional theranostics for hypoxic tumors.

Perfluoro-tert-butanol: a cornerstone for high performance fluorine-19 magnetic resonance imaging.

As a versatile quantification and tracking technology, 19F magnetic resonance imaging (19F MRI) provides quantitative "hot-spot" images without ionizing radiation, tissue depth limit, and background interference. However, the lack of suitable imaging agents severely hampers its clinical application. First, because the 19F signals are solely originated from imaging agents, the relatively low sensitivity of MRI technology requires high local 19F concentrations to generate images, which are often beyond the reach of many 19F MRI agents. Second, the peculiar physicochemical properties of many fluorinated compounds usually lead to low 19F signal intensity, tedious formulation, severe organ retention, etc. Therefore, the development of 19F MRI agents with high sensitivity and with suitable physicochemical and biological properties is of great importance. To this end, perfluoro-tert-butanol (PFTB), containing nine equivalent 19F and a modifiable hydroxyl group, has outperformed most perfluorocarbons as a valuable building block for high performance 19F MRI agents. Herein, we summarize the development and application of PFTB-based 19F MRI agents and analyze the strategies to improve their sensitivity and physicochemical and biological properties. In the context of PFC-based 19F MRI agents, we also discuss the challenges and prospects of PFTB-based 19F MRI agents.

Critical biodegradation process of a widely used surfactant in the water environment: dodecyl benzene sulfonate (DBS).

Sodium dodecyl benzene sulfonate (DBS) is a widely used surfactant that is now found extensively in water bodies because of anthropogenic emissions. Since the degradation of DBS in the environment mainly relies on microorganisms, it is essential to study the mechanism by which DBS is biodegraded. In this study, Chlorella vulgaris was used to research the biodegradation process of DBS. The C. vulgaris suspension was centrifuged to remove the supernatant, then secondary deionized water and DBS were added to the C. vulgaris. And the intermediate products were detected in real time by electrospray ionization mass spectrometry (ESI-MS). Some novel intermediate products, including 4-sodium sulfophenyldodecanoate acid and its homologs, were detected that had not been mentioned in previous studies. In this work, the process of DBS degradation was indicated, which consisted of three main steps: chain-shorting oxidation, ring-opening oxidation of benzene rings, and degradation of small molecules. By investigating the process of DBS degradation by C. vulgaris, we were able to propose a preliminary mechanism of DBS biodegradation, which is of great significance for research on the migration and conversion of surfactants in the environment.

Facile Hydrothermal Synthesis of Chlorella-Derived Environmentally Friendly Fluorescent Carbon Dots for Differentiation of Living and Dead Chlorella.

The judgment of microalgae viability is a vital procedure in the process of microalgae culture and treatment, which also plays an important role in bioremediation, bioindication, and pharmacology fields. The current conventional methods for defining living/dead microalgal cells are complicated or laborious. Hence, developing a simple and reliable detection method for microalgae viability is still challenging. Here, we developed chlorella-based carbonized polymer dots (c-CPDs) by a hydrothermal method. Due to their small average size of 5.0 nm, obvious excitation-dependent emission, stable fluorescence properties, and low toxicity, c-CPDs could be used for distinguishing living or dead chlorella by testing different fluorescence characteristics of c-CPD-labeled chlorella. Compared with conventional cellular dyes used for differentiating living/dead microalgae, c-CPDs significantly reduced toxicity, showing good sensitivity and reliability. This work provided a method to prepare environmentally friendly carbon dots (CDs) using microalgae, which had potential to be prepared on a large scale and might be applied feasibly in the preparation of doped CDs by controlling the growth of chlorella.

Novel sulfonated poly(ether ether ketone)/triphenylamine hybrid membrane for vanadium redox flow battery applications.

A novel sulfonated poly(ether ether ketone)/triphenylamine hybrid membrane with various triphenylamine loadings (1%, 2% and 5%) has been successfully fabricated. Optimum triphenylamine loading was confirmed by exploring the physicochemical properties and morphology of different membranes. The hybrid membrane exhibited lower vanadium permeability than pristine SPEEK membranes due to the acid-base interaction between amine groups and sulfonated groups. Introduction of triphenylamine also improved the proton conductivity because the nitrogen atom of triphenylamine can be protonated and contribute to the proton transfer. As the result, the hybrid membrane demonstrated higher ion selectivity compared with SPEEK and Nafion115 membranes. The VRFB single cell with SPEEK/TPAM-1% membrane showed better performance compared to a Nafion115 membrane at the current density of 60 mA cm-2. The SPEEK/TPAM hybrid membrane has great potential for VRFB application.

Evaluation of performance in a combined UASB and aerobic contact oxidation process treating acrylic wastewater.

The lab-scale and full-scale performance of a combined mesophilic up-flow anaerobic sludge blanket (UASB) and aerobic contact oxidation (ACO) process for treating acrylic wastewater was studied. During lab-scale experiment, the overwhelmed volumetric load for UASB was above 6 kg chemical oxygen demand (COD) ·(m(-3)·d(-1)) since COD removal efficiency dropped dramatically from 73% at 6 kg COD·(m(-3)·d(-1)) to 61% at 7 kg COD·(m(-3)·d(-1)) and 53% at 8 kg COD·(m(-3)·d(-1)). Further results showed that an up-flow fluid velocity of 0.5 m h(-1) for UASB obtained a highest COD removal efficiency of 75%, and the optimum COD volumetric load for the corresponding ACO was 1.00 kg COD·(m(-3)·d(-1)). Based on the configuration of the lab-scale experiment, a full-scale application with an acrylic wastewater treatment capacity of 8 m3 h(-1) was constructed and operated at a volumetric load of 5.5 kg COD·(m(-3)·d(-1)), an up-flow fluid velocity of 0.5 m h(-1) for UASB and a volumetric load of 0.9 kg COD·(m(-3)·d(-1)) for ACO; and the final effluent COD was around 740 mg L(-1). The results suggest that a combined UASB-ACO process is promising for treating acrylic wastewater.