Latest ArticlesAn intramolecular selenocyclizations of olefins mediated by a commercially available hypervalent iodine(III) reagent, PhIO, was developed. This method provided access to a wide range of selenenylated heterocycles under ambient conditions. The striking advantages of this protocol over all previous methods include mild reaction conditions, easy operation, good yields, high levels of functional group compatibility, large–scale application and suitability for the late-stage functionalization of complex molecules of biological importance.
To enhance the photodegradation ability of CeO2 for organic dyes, an effective strategy is to introduce oxygen vacancies (Vo). In general, the introduced Vo are simultaneously present both on the surface and in the bulk of CeO2. The surface oxygen vacancies (Vo-s) can decrease the band gap, thus enhancing light absorption to produce more photogenerated e− for photodegradation. However, the bulk oxygen vacancies (Vo-b) will inhibit photocatalytic activity by increasing the recombination of photogenerated e− and Vo-b. Therefore, regulating the concentrations of Vo-s to Vo-b is a breakthrough for achieving the best utilization of photogenerated e− during photodegradation. We used an easy hydrothermal method to achieve tunable concentrations of Vo-s to Vo-b in CeO2 nanorods. The optimized CeO2 presents a 70.2% removal of rhodamine B after 120 min of ultraviolet−visible light irradiation, and a superior photodegradation performance of multiple organics. This tuning strategy for Vo also provides guidance for developing other advanced metal-oxide semiconductor photocatalysts for the photodegradation of organic dyes.
We herein report a new lanthanide metal-organic framework (MOF) that exhibits excellent chemical stability, especially in the aqueous solution over a wide pH range from 1 to 14. In contrast to many reported lanthanide MOFs, this Tb-based MOF emits cyan fluorescence inherited from the integrated AIE-active ligand, rather than Ln3+ ions. More remarkably, its fluorescence signal features a highly selective and sensitive "turn-off" response toward CrO42−, Cr2O72− and Fe3+ ions, highlighted with the low detection limits down to 68.18, 69.85 and 138.8 ppm, respectively. Thus, the exceptional structural stability and sensing performance render this material able to be a superior luminescent sensor for heavy metal ions in wastewater.
A novel approach for the synthesis of 4-aminoquinazolines has been developed via rhodium(III)-catalyzed [4 + 2] annulation of N-arylbenzamidines with 1, 4, 2-dioxazol-5-ones. This reaction features excellent regioselectivity, broad substrate scope and high step economy, which would provide the reference for the construction of the fused 4-aminoquinazolines with biologically and pharmacologically active compounds.
The fascinating luminescence properties of gold nanoclusters (AuNCs) have drawn considerable research interests, and been widely harnessed for a wide range of applications. However, a fundamental understanding towards ligand density's role in the luminescence properties of these ultrasmall AuNCs remains unclear yet. In this communication, through systematic investigation of surface chemistries of glutathione-protected AuNCs (GSH-AuNCs) with different density of GSH as well as other thiolates, it is discovered that the density of surface ligands can significantly regulate the luminescence properties of AuNCs. Fluorescence lifetime spectroscopy and X-ray photoelectron spectroscopy showed that AuNCs with a higher density of electron-rich ligands facilitate their luminescence generation. Moreover, differences in the surface coverage of AuNCs can also affect their interactions with foreign species, as illustrated by significantly different fluorescence quenching capability of GSH-AuNCs with different ligand density towards Hg2+. This study provides new insight into the intriguing luminescence properties of metal NCs, which is hoped to stimulate further research on the design of metal NCs with strong luminescence and sensitive/specific responses for promising optoelectronic, sensing and imaging applications.
The photoisomerization properties of azo derivatives have been widely used in the fields of materials and biology. One serious restriction to the development of functional azo-based materials is the necessity to trigger switching by UV light, which damage the corresponding surfaces and penetrate only partially through the matter. Therefore, developing the visible and near-infrared light activated azo switches can solve this problem. This review provides a summary of molecular design strategies for driving the isomerization of azo derivatives with visible light and near-infrared light: (1) smart design directly excited by visible light, (2) the addition of upconversion nanoparticles, (3) the employment of two-photon absorption, (4) indirect excitation in combination with metal sensitizer.
Living-cell imaging demands high specificity, sensitivity, and minimal background interference to the targets of interest. However, developing a desirable imaging probe that can possess all the above features is still challenging. The bioorthogonal surface-enhanced Raman scattering (SERS) imaging has been recently emerged through utilizing Raman reporters with characteristic peaks in Raman-silent region of cells (1800-2800 cm-1), which opens a revolutionary avenue for living-cell imaging with multiplexing capability. In this review, we focus on the recent advances in the technology development and the biological and biomedical applications of the living-cell bioorthogonal SERS imaging technique. After introduction of fundamental principles for bioorthogonal tag or label, we present applications for visualization of various intracellular components and environment including proteins, nucleic acids, lipids, pH and hypoxia, even for cancer diagnosis in tissue samples. Then, various bioorthogonal SERS imaging-guided therapy strategies have been discussed such as phototherapy and surgery. In conclusion, this strategy has great potential to be a flexible and robust tool for visualization detection and diseases diagnosis.
Currently, architecting a rational and efficient nanoplatform combing with multi-therapeutic modalities is highly obligatory for advanced cancer treatment. In order to remedy the self-limiting hypoxic dilemma of photodynamic therapy (PDT), herein, a facile photosensitizer (i.e., chlorin e6, Ce6) and bioreductive prodrug (i.e., tirapazamine, TPZ)-coloaded hyaluronic acid (HA) nanomicelles (denoted as TPZ@HA-Ce6) was developed for the cascading mode of photo-bioreductive cancer therapy. Taking the typical advantage of Ce6 coupled HA conjugate, TPZ was easily and successfully accommodated into the hydrophobic core of HA-Ce6 nanomicelles, yielding TPZ@HA-Ce6. It showed good dispersibility and stability with the hydrodynamic size of ca. 170 nm. It targeted the CD44 overexpressed cancer cells by receptor-mediated endocytosis way and killed them effectively with singlet oxygen and the subsequent TPZ radicals resulting from the oxygen depletion of PDT. The later was further verified by the hypoxia probe in vivo. Using murine mammary carcinoma 4 T1 model, TPZ@HA-Ce6 nanomicelles exhibited cascading and synergistic anticancer effect of PDT and TPZ bioreductive therapy compared with each monotherapy. This work suggests the promising prospect of the hybrid hyaluronic nanomicelles for highly efficient cancer combination treatment.
Sulfoxonium ylides as carbene precursors couple smoothly with thioureas in the presence of 5 mol% of rhodium(Ⅱ) acetate dimmer via carbenoid insertion to afford the corresponding 2-aminothiazoles with high chemoselectivity, providing a facile and efficient approach to access a variety of 2-aminothiazole derivatives with good functional groups tolerance.
Recently, the degradation of organic compounds in saline dye wastewater by sulfate radicals (SO4·-)-based advanced oxidation processes (AOPs) have attracted much attention. However, previous studies on these systems have selected non-chlorinated dyes as model compounds, and little is known about the transformation of chlorinated dyes in such systems. In this study, acid yellow 17 (AY-17) was selected as a model of chlorinated contaminants, and the degradation kinetics and evolution of oxidation byproducts were investigated in the UV/PDS system. AY-17 can be efficiently degraded (over 98% decolorization) under 90 min irradiation at pH 2.0–3.0, and the reaction follows pseudo-first order kinetics. Cl- accelerated the degradation of AY-17, but simultaneously led to an undesirable increase of absorbable organic halogen (AOX). Several chlorinated byproducts were identified by liquid chromatography-mass spectrometry (LC–MS/MS) in the UV/PDS system. It indicates that endogenic chlorine and exogenic Cl– reacted with SO4·- to form chloride radicals, which are involved in the dechlorination and rechlorination of AY-17 and intermediates. The possible degradation mechanisms of AY-17 photooxidative degradation are proposed. This work provides valuable information for further studies on the role of exogenic chloride in the degradation of chlorinated azo dyes and the kinetic parameters in the PDS-based oxidation process.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
