Latest ArticlesPBQ [1-(4-chlorophenyl)-3-(pyridin-3-yl)urea], an enormous potent molluscicide, showed excellent Pomacea canaliculata (P. canaliculata) control activity and low toxicity for other aquatic organisms, but its snail-killing mechanisms are still not fully understood. We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe, NCV. As the viscosity in the test solutions increased, compared with that in pure ethanol, a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90% glycerol. Furthermore, NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells. The liver, stomach, and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times. A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h, which highlighted an increase in viscosity. Hematoxylin and eosin (HE) staining further supported PBQ-induced liver damage with a viscosity increase in P. canaliculata. Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.
In our work, polymorphism strategy has been successfully applied to tune up chromism and luminescence properties of viologen-based materials. Two polymorphs of viologen-based complexes of α-CdBr2(PHSQ)2(H2O)2 (1) and β-CdBr2(PHSQ)2(H2O)2 (2) (PHSQ = N-(4-sulfophenyl)-4,4′-bipyridinium) were synthesized by changing the solvent. They can both respond to UV light and electricity in the manner of chromism visible to the naked eye and the coloration states have good reversibility, through which an inkless erasable printing model has been established. But the coloration contrast of 1 is higher compared to 2. Meanwhile, they both exhibit photoluminescence properties and the intensity of 1 is twice that of 2, which is accompanied by photoquenching upon continuous UV light irradiation. The only divergence of disordered/ordered O atoms in the two crystalline compounds leads to significantly different chromic and luminescent properties. Further explorations simultaneously demonstrate that the different chromic performance between 1 and 2 should attribute to the alteration of stimulus-induced (light/ electricity) electron transfer channels caused by the ordered/disordered O atoms in the complexes, which is achieved through CH···O and OH···O interactions to change crystal arrangement and structural rigidity, thus affect luminescent properties.
Quantitative determination of tetracycline (TC) in environment and foods is of great importance, as excessive residues might have negative effects on human health and environmental risks. Herein, a self-powered molecularly imprinted photoelectrochemical (PEC) sensor based on the ZnO/C photoanode and the Fe-doped CuBi2O4 (CBFO) photocathode is developed for the sensitive detection of TC. The photocathodic current can be amplified by the efficient electron transfer caused by the Fermi energy level gap between the photoanode and photocathode. Furthermore, molecularly imprinted polymers (MIPs) at photocathode can selectivity identify the TC templates and thus improve the specificity. Under the optimal conditions, the sensor has a linear range of 10‒2–1.0 × 105 nmol/L, and a limit of detection (LOD) of 0.007 nmol/L (S/N = 3). More crucially, the milk sample detection is carried out using the as-prepared sensor, and the outcome is satisfactory. The research gives us a novel sensing platform for quick and accurate antibiotic (like TC) in environment and food monitoring.
Metal complexes hold significant promise in tumor diagnosis and treatment. However, their potential applications in photodynamic therapy (PDT) are hindered by issues such as poor photostability, low yield of reactive oxygen species (ROS), and aggregation-induced ROS quenching. To address these challenges, we present a molecular self-assembly strategy utilizing aggregation-induced emission (AIE) conjugates for metal complexes. As a proof of concept, we synthesized a mitochondrial-targeting cyclometalated Ir(III) photosensitizer Ir-TPE. This approach significantly enhances the photodynamic effect while mitigating the dark toxicity associated with AIE groups. Ir-TPE readily self-assembles into nanoaggregates in aqueous solution, leading to a significant production of ROS upon light irradiation. Photoirradiated Ir-TPE triggers multiple modes of death by excessively accumulating ROS in the mitochondria, resulting in mitochondrial DNA damage. This damage can lead to ferroptosis and autophagy, two forms of cell death that are highly cytotoxic to cancer cells. The aggregation-enhanced photodynamic effect of Ir-TPE significantly enhances the production of ROS, leading to a more pronounced cytotoxic effect. In vitro and in vivo experiments demonstrate this aggregation-enhanced PDT approach achieves effective in situ tumor eradication. This study not only addresses the limitations of metal complexes in terms of low ROS production due to aggregation but also highlights the potential of this strategy for enhancing ROS production in PDT.
Metal-organic frameworks (MOFs) with superior physicochemical properties have great potential for applications in chromatographic separation. However, currently popular methods for the synthesis of MOF-based silica composite materials usually require the use of harmful organic solvents and long-term high-temperature sealing reactions. In order to respond to the needs of green chromatography, it is urgent to develop a new green organic-solvent-free strategy for the synthesis of MOF@SiO2 composites. MIP-202 is a zirconium-MOF constructed from zirconium ion and l-aspartic acid, which features green synthesis as well as good hydrolytic stability and chemical stability. In this paper, SiO2-NH2 was first prepared in a hydrophilic deep eutectic solvent, and then an amino acid-based MOF material (MIP-202) was modified on the surface of the SiO2-NH2 in an aqueous solution to obtain a MIP-202@SiO2 composite material. The multi-mode separation performance of MIP-202@SiO2 as a promising liquid chromatographic stationary phase was particularly evaluated and the separation mechanisms were discussed. The MIP-202@SiO2 column exhibited excellent separation ability for aromatic positional isomers. In addition, chiral enantiomers and hydrophilic analytes were also satisfactorily detected and separated. This work provides a new approach for the facile synthesis of MOF-based liquid chromatographic separation material by using green deep eutectic solvent and water as the reaction media.
Recently circularly polarized luminescence (CPL) materials have attracted significant interest. Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields, such as in high-level information encryption. Here, we provided a novel and general strategy involving handedness-selective filtration and ground-state chiral self-recovery (CSR) in double film system to address this issue. Based on this strategy, we achieved CPL switch through the reversible modulation of ground-state chirality including absorption and scattering circular dichroism (CD) signals over the full UV-visible wavelength range (365-700 nm) in a single azobenzene polymer (PAzo) film. More importantly, by flexibly changing the type of fluorescent films, it is convenient to achieve general excited-state CSR, that is reversible switching of full-color including ideal white (CIE coordinate (0.33, 0.33)), as well as room-temperature phosphorescent CPL. All these CPL signals without almost any intensity decay after three cycles of on-and-off switching. Experimental results indicated that the trans-cis isomerization and ordered rearrangement of azobenzene units in PAzo film were the fundamental reasons for realizing CPL switching. Finally, based on this system we achieved dynamic visual encryption and decryption process including multiple decryption methods. This study provides an effective method for constructing a universally applicable chiroptical switch in excited state.
Catalytic oxidation of soot is of great importance for emission control on diesel vehicles. In this work, a highly active Cs/Co/Ce-Sn catalyst was investigated for soot oxidation, and it was unexpectedly found that high-temperature calcination greatly improved the activity of the catalyst. When the calcination temperature was increased from 500 ℃ to 750 ℃, T50 decreased from 456.9 ℃ to 389.8 ℃ in a NO/O2/H2O/N2 atmosphere. Characterization results revealed that high-temperature calcination can promote the ability to transfer negative charge density from Cs to other metal cations in Cs/Co/Ce-Sn, which will facilitate the production of more oxygen defects and the generation of more surface-active oxygen species. Surface-active oxygen species are beneficial to the oxidation of NO to NO2, leading to the high yield of NO2 exploitation. Therefore, the Cs/Co/Ce-Sn catalyst calcined at 750 ℃ demonstrated higher activity than that calcined at 500 ℃. This work provides a pathway to prepare high efficiency catalysts for the removal of soot and significant insight into the effects of calcination on soot oxidation catalysts.
An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography. Analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and elemental analysis, etc., confirmed the successful prepared of this innovative stationary phase. The unique combination of amide, long alkyl chain, and imidazole ring in the hydrogel coating enables the stationary phase to function effectively in hydrophilic/reversed-phase/ion exchange liquid chromatography. Notably, the stationary phase exhibited superior separation performance owing to the synergistic effect of the ionic liquid and hydrogel. This was particularly evident when analyzing various analytes such as organic acids, nucleosides/bases, polycyclic aromatic hydrocarbons (PAHs) and anions. Furthermore, under our operating conditions, an excellent column efficiency of 53, 642.9 plates/m was achieved for theobromine. In summary, we have proposed a straightforward strategy to enhance the separation performance of hydrogel coatings in liquid chromatography, thereby broadening the potential applications of hydrogels in the field of separation.
Poly(butylene adipate-terephthalate) (PBAT), as one of the most common and promising biodegradable plastics, has been widely used in agriculture, packaging, and other industries due to its strong biodegradability properties. It is well known that PBAT suffers a series of natural weathering, mechanical wear, hydrolysis, photochemical transformation, and other abiotic degradation processes before being biodegraded. Therefore, it is particularly important to understand the role of abiotic degradation in the life cycle of PBAT. Since the abiotic degradation of PBAT has not been systematically summarized, this review aims to summarize the mechanisms and main factors of the three major abiotic degradation pathways (hydrolysis, photochemical transformation, and thermochemical degradation) of PBAT. It was found that all of them preferentially destroy the chemical bonds with higher energy (especially C-O and C=O) of PBAT, which eventually leads to the shortening of the polymer chain and then leads to reduction in molecular weight. The main factors affecting these abiotic degradations are closely related to the energy or PBAT structure. These findings provide important theoretical and practical guidance for identifying effective methods for PBAT waste management and proposing advanced schemes to regulate the degradation rate of PBAT.
Chloroform is a common and excellent solvent for preparing high-efficient organic solar cells (OSCs), however, it is toxic and poisonable chemical. In comparisons, deuterated chloroform (DC) is less toxic and costly, and particularly, it is non-poisonable chemical. In this paper, we use DC to replace ultra-dry chloroform (UC) as the processing solvent for preparation of active layers of organic solar cells. First, we selected PM6:BTP-eC9 as the basic binary and counted 100 solar cells' data, from which comparable device performance were obtained with use of DC and UC. Interestingly, DC showed better reproducibility, superior storage under a nitrogen atmosphere and a little better performance than UC. Both DC and UC gave rise of comparable hole and electron mobilities and similar charge recombination losses. Second, we based PM6:Y6 and D18-Cl: Y6 as the binaries and similar effects were obtained from both UC and DC when counting 30 devices for each binary. Third, the universality of the use of DC for preparing high-efficient OSCs were again checked with several binary and ternary systems. In all, this study demonstrate that DC can replace UC for use in the field of OSCs.
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