Efficient decontamination of ciprofloxacin at neutral pH via visible light assisted Fenton-like process mediated by Fe(III)-GLDA complexation.

This work demonstrated a novel N,N-bis(carboxymethyl)glutamic acid (GLDA) modified visible (vis) light assisted Fenton-like system which could effectively removal ciprofloxacin (CIP) at neutral pH. The removal rate of CIP in the GLDA/Fe(III)/H2O2/vis system was 97.9% within 120 min and was approximately twice as high as that in the Fe(III)/H2O2/vis system. GLDA could significantly accelerate the Fe(III)/Fe(II) cycle under visible light irradiation. Radical scavenging experiments demonstrated that 74.2% of the Fe(II) in the GLDA/Fe(III)/H2O2/vis system originated from the ligand-to-metal charge transfer reaction between Fe(III) and GLDA. The hydroxyl radical was the dominant species for CIP degradation. H2O2 utilization kinetic modeling exhibited that 90.1% of H2O2 was used for CIP mineralization. The effects of experimental parameters and coexisting substances on the removal of CIP in the Fe(III)/GLDA/H2O2/vis system were investigated in detail. The intermediate products of CIP were explored via the high-performance liquid chromatography-mass spectrometry.

Enhancing Fenton-like process at neutral pH by Fe(III)-GLDA complexation for the oxidation removal of organic pollutants.

N,N-bis(carboxymethyl)glutamic acid (GLDA) was utilized in this study to significantly enhance the Fe(III) mediated Fenton-like oxidation removal of organic pollutants at neutral pH, in which ciprofloxacin (CIP) was used as the model pollutant. The CIP degradation rate in the GLDA/Fe(III)/H2O2 system reached 96.5% within 180 min and was nearly 14 times higher than that in the Fe(III)/H2O2 system. This enhancement was contributed to the acceleration of the cycle of Fe(III)/Fe(II) caused by GLDA, which was verified by UV-vis spectroscopy, cyclic voltammetry, and radical quenching experiments. The results proved that the GLDA could complex with Fe(III) and greatly modify the redox potential of Fe(III)/Fe(II). Moreover, radical quenching experiments confirmed that •OH and O2·- were the mainly species for CIP degradation, and O2·- was responsible for 81.9% •OH generation. In addition, H2O2 utilization kinetic modeling was also investigated. The optimum parameters of the 100 µM Fe(III)-GLDA complex and 15 mM H2O2 were attained by lot-size optimization experiments. Two possible CIP degradation pathways were proposed on the basis of the intermediates identified by MS/MS. The GLDA/Fe(III)/H2O2 system performed better than common chelating agents at the same condition, manifesting good potential for environmental concerns.

Perovskite Light-Emitting Diodes with EQE Exceeding 28% through a Synergetic Dual-Additive Strategy for Defect Passivation and Nanostructure Regulation.

Quasi-2D perovskites have long been considered to have favorable "energy funnel/cascade" structures and excellent optical properties compared with their 3D counterparts. However, most quasi-2D perovskite light-emitting diodes (PeLEDs) exhibit high external quantum efficiency (EQE) but unsatisfactory operating stability due to Auger recombination induced by high current density. Herein, a synergetic dual-additive strategy is adopted to prepare perovskite films with low defect density and high environmental stability by using 18-crown-6 and poly(ethylene glycol) methyl ether acrylate (MPEG-MAA) as the additives. The dual additives containing COC bonds can not only effectively reduce the perovskite defects but also destroy the self-aggregation of organic ligands, inducing the formation of perovskite nanocrystals with quasi-core/shell structure. After thermal annealing, the MPEG-MAA with its CC bond can be polymerized to obtain a comb-like polymer, further protecting the passivated perovskite nanocrystals against water and oxygen. Finally, state-of-the-art green PeLEDs with a normal EQE of 25.2% and a maximum EQE of 28.1% are achieved, and the operating lifetime (T50 ) of the device in air environment is over ten times increased, providing a novel and effective strategy to make high efficiency and long operating lifetime PeLEDs.

Alkylpolyglycoside modified MnFe2O4 with abundant oxygen vacancies boosting singlet oxygen dominated peroxymonosulfate activation for organic pollutants degradation.

A novel alkylpolyglycoside (APG)-modified MnFe2O4 nanocomposite (APG@MnFe2O4) enriched with oxygen vacancies (VOs) was developed via co-precipitation and characterized as a peroxymonosulfate (PMS) activator to degrade 2,4-dichlorophenol (2,4-DCP) as the model contaminant. The APG effectively promoted the in situ formation of VOs on MnFe2O4 and subsequently enhanced the production of singlet oxygen (1O2). Furthermore, the APG@MnFe2O4 initialized an even more efficient non-radical pathway and dominated the degradation of 2,4-DCP. The constructed APG@MnFe2O4 exhibited a much higher reaction rate constant (0.0522) by ~12.73 times of that of the bare MnFe2O4 (0.0041). The degradation efficiency of 2,4-DCP in the APG@MnFe2O4/PMS system approached 93% within 90 min, a rate significantly higher than that in the MnFe2O4/PMS system (32%) given the same condition. The reasonable catalytic mechanism can be attributed to the Fe/Mn/VOs species. The APG@MnFe2O4 also exhibits universally high removal activity for various pollutants and excellent cyclic stability. Thus, the APG@MnFe2O4 is a promising PMS activator, and its utilization offers a useful strategy for developing VOs-enriched MnFe2O4 catalysts as a means of eliminating organic pollutants from wastewater.

A mitochondria-targeted single fluorescence probe for separately and continuously visualizing H2S and Cys with multi-response signals.

Hydrogen sulfide and cysteine are momentous endogenous regulators of many physiological processes and maintain a dynamic balance of redox in living organisms. To investigate the inter-relationship of them in vivo, there is a pressing need to develop analytical molecular tools to identify related biomolecules. We construct a mitochondria-targeted single fluorescence probe (Mit-CM) for separately and continuously visualizing H2S, Cys and H2S/Cys with multi-response fluorescence signals. Mit-CM has the following advantages: (Ⅰ) colorimetric and ratiometric: two well-separated emission bands can ensure accurate detection of the analyte and significant color changes contribute to rapid identification of the analyte by the naked eye; (Ⅱ) mitochondrial localization: study the physiological functions of H2S and Cys in mitochondria; (Ⅲ) separate and continuous detection of H2S and Cys: reveal the inter-relationship and interconversion of them in biological system. Moreover, the desirable attributes of low cytotoxicity, better biocompatibility and excellent mitochondria enrichment ability indicate that Mit-CM can be employed to achieve detection and observe distribution of H2S, Cys and H2S/Cys in living organism.

A novel fluorescent probe for rapidly detection cysteine in cystinuria urine, living cancer/normal cells and BALB/c nude mice.

Cysteine (Cys), an important organic small molecule containing sulfhydryl groups, plays paramount functions in human pathologies and physiologies. The detection of Cys in living vivo is essential for studying its roles. Here, we designed and synthesized a novel red-emission fluorescent probe AXPI-Cys with highly sensitivity (LOD = 48.9 ±â€¯0.23 nM), rapidly response (<7 min) and colorimetric for detection cysteine. More importantly, the AXPI-Cys was determined Cys in real cystinuria urine samples for the first time with the satisfactory results (92%-99.96%) and employed for specifically location of endogenous/exogenous Cys in living cancer/normal cells and almost non-toxic, that is very valuable for diagnosis of cystinuria and observation of the distribution of Cys in normal cells. Notably, the AXPI-Cys was applied to imaging Cys in BALB/c nude mice with good biocompatibility and desirable tissue-penetration depth. Owing to the superior capability of AXPI-Cys, it provided a desired method to detect Cys in urine samples and cells, and exhibited munificent potential usage in biosystems and imaging studies in vivo.

Molecular Engineering of Thermally Activated Delayed Fluorescence Emitters with Aggregation-Induced Emission via Introducing Intramolecular Hydrogen-Bonding Interactions for Efficient Solution-Processed Nondoped OLEDs.

Purely organic luminescent materials concurrently exhibiting thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) features are in great demand due to their high efficiency in aggregation-state toward efficient nondoped OLEDs. Herein, a class of TADF emitters adopting phenyl(pyridyl)methanone as electron-accepting segments and di(tert-butyl)carbazole and 9,9-dimethyl-9,10-dihydroacridine (or phenoxazine) as electron-donating groups are designed and synthesized. The existence of intramolecular hydrogen bonding is conducive to minish the energy difference between a singlet and a triplet (ΔEst), suppress nonradiative decay, and increase the luminescence efficiency. By using 3CPyM-DMAC as the emitter, the nondoped device via a solution process realize a high current efficiency (CE) and external quantum efficiency (EQE) of 35.4 cd A-1 and 11.4%, respectively, which is superior to that of CBM-DMAC with a CE and EQE of 14.3 cd A-1 and 6.7%. This work demonstrates a promising tactic to the establishment of TADF emitters with AIE features via introducing intramolecular hydrogen bonding.

Dual-Functional NIR AIEgens for High-Fidelity Imaging of Lysosomes in Cells and Photodynamic Therapy.

Design and synthesis of water-soluble near-infrared (NIR) emissive fluorescent molecules with aggregation-induced emission (AIE) characteristics, perfect signal-to-noise ratio for imaging of organelle, and photodynamic therapy (PDT) functions has received enormous attention. However, the dual-functional NIR AIEgens of high-fidelity tracking lysosome and ablation cancer cells was rarely reported. Herein, a series of AIE luminogens (AIEgens) with a typical AIE effect, good biocompatibility, superior photostability, high brightness, and excellent reactive oxygen species (ROS) generation ability were developed, which had different electronic push-pull strength and conjugate system size in the molecular structure. These AIEgens could specifically "light up" and dynamically long-term track the lysosomes in living cells and zebrafish with ultrahigh colocalization imaging Pearson's correlation coefficients (Rr: 0.9687) and overlap coefficient (R: 0.9967). Additionally, the MPAT of NIR luminescence as a photosensitizer was used for photodynamic ablation of cancer cells, owing to prompt generation of the ROS under green light irradiation (495-530 nm, 10 mW cm-2). Hence, this research not only expands the application range of NIR AIEgens but also provides useful insights into design of split-new method for the treatment of cancer.