Latest ArticlesSynthesizing 2-deoxyglycosides, prevalent motifs in bioactive molecules, presents significant challenges in stereocontrol and functional group tolerance. We report a metal-free, photo-induced O-glycosylation of glycals using acridinium salts under visible light. This method effectively couples diverse glycals with both carboxylic acids and alcohols, providing facile access to α-2-deoxyglycosides under mild conditions with broad substrate scope and functional group compatibility. The protocol exhibits high α-stereoselectivity with carboxylic acids and moderate α-selectivity with alcohols, enabling late-stage functionalization of complex molecules, including amino acids, peptides, and drugs. Mechanistic experiments implicate the possible involvement of radical intermediates, potentially operating via a chain reaction. Notably, 2-deoxyglycosylation of NSAIDs using this method enhanced their neuroprotective properties in vitro. This photo-induced strategy offers a practical and versatile platform for accessing complex 2-deoxyglycans relevant to medicinal chemistry and chemical biology.
Glial fibrillary acidic protein (GFAP) can serve as a promising early blood biomarker for Alzheimer's disease (AD). Existing assays mostly rely on antibody-based detection technologies, the preparation of antibodies is relatively complex, costly, and requires high storage conditions. In this study, we screened an aptamer specifically targeting GFAP (KD = 0.621 µmol/L) through systematic evolution of ligands by exponential enrichment (SELEX) technique for the first time and then applied which to develop a simple but sensitive fluorescent sensor by combining isothermal exponential amplification reaction (EXPAR) with hybridization chain reaction (HCR). The platform achieved a broad linear detection range (10 pg/mL to 10 µg/mL) and a low detection limit (0.24 pg/mL). The results detected by the proposed sensor were highly correlated with that detected by ELISA method (R = 0.9989, P < 0.0001). The work overcomes the limitations of antibody-based technologies and provides a promising solution for early diagnosis of AD.
The development of innovative strategies for inert B–H bond functionalization of carboranes and exploration of their potential applications represents a central task in organic chemistry. Here, we demonstrate the facile B–H bond functionalization in carboranes through a cage···Ⅰ(Ⅲ) interaction between a nido-carborane cluster and a hypervalent iodine(Ⅲ) unit. Both experimental and theoretical investigations reveal that the cage···Ⅰ(Ⅲ) interaction induces a charge transfer from the boron cage to the iodine moiety, which leads to a significant decrease of the negative charge at the B(9)–H site of nido-carborane. This facilitates the activation of the B–H bond and subsequent chemical transformations. The unprecedented cage···Ⅰ(Ⅲ) interaction offers a similar B–H bond activation mode as metal mediation. Furthermore, the treatment of nido-carboranes with the iodide(Ⅲ) reagent of PhI(OAc)2 affords nido-carborane-phenyl iodonium zwitterions as versatile synthons, which enable the modular construction of exopolyhedral B–O, B–N, B–P, and B–S bonds of carborane derivatives. This approach provides an efficient and scalable synthetic platform for metal-free and site-selective B–H bond functionalization of nido-carboranes under mild conditions. Notably, the developed 2D-3D fused structures can be used as ligands for the facile construction of novel boron cluster-fused hetero-polycyclic metal complexes in one step. These compounds demonstrate intriguing photophysical properties including aggregation-induced emission, tunable emission wavelength, and oxygen sensing.
Metal-organic frameworks (MOFs) with tunable structures provide a versatile platform for exploring active sites and show great potential in enzyme-like catalysis. In this study, arginine was employed as a modulator to synthesize an arginine-copper metal-organic framework (Arg-Cu-MOF), which demonstrated superior peroxidase-like activity and stability in comparison to unmodified Cu-MOF. The improved activity resulted from an increased density of Cu+ active sites, facilitating efficient •OH generation through H2O2 decomposition. Glyphosate interacts with the copper sites in a way that affects •OH generation and chromogenic substrate oxidation, leading to detectable colorimetric changes. By integrating Arg-Cu-MOF into a needle sensor, we allowed sample handling, reagent mixing, and signal readout, enabling both precise instrumental measurements and semi-quantitative visual detection of glyphosate. This sensor offers a detection range of 0.05–200 µg/mL with a detection limit of 0.049 µg/mL. This work highlights the potential of MOF modulation strategies and integrated detection platforms to enhance analytical performance, improve user-friendliness, and expand the application scope of biomimetic nanomaterials.
The host-guest doped strategy has become the main method for constructing organic phosphorescence materials. In the doped system, guest molecules emit phosphorescence, therefore, improving the luminescence performance of guests is the key to optimizing the phosphorescence property of the doped materials. Herein, we designed to introduce the carbonyl group on the guest molecules. Carbonyl group can effectively promote n-π* transitions, thereby increasing the spin-orbit coupling (SOC) constant of the guests, ultimately improving the phosphorescence performance of the doped materials. Using the indazole derivative (IZ) as the initial guest, two other guests containing carboxyl group (IZ-CG) or ethoxycarbonyl group (IZ-EG) were successfully obtained. Further selected two small molecules and two polymers as the hosts to construct four doped systems. Among these doped systems, the phosphorescence performance of doped materials with IZ-CG or IZ-EG as the guest is significantly better than that of doped materials with IZ as the guest. The phosphorescence lifetime has increased by 2.3-5.0 times, and the phosphorescence quantum yield has increased by 3.0-5.7 times. Theoretical calculations and single crystal structures indicated that carbonyl groups can not only increase the SOC constant, but also enhance the intermolecular interactions of the guests. In addition, doped material can be effectively used for imaging subcutaneous and lymph nodes in mice, achieving a high signal-to-noise ratio.
Hydrogels, soft materials made from polymer networks capable of absorbing water, demonstrate remarkable compatibility in diverse hybridizations. When the fillers that can undergo reversible crystallization are used for incorporation, the materials’ mechanical properties and functions would be significantly improved. Therefore, these hydrogels, named crystal hydrogels, are emerging as a class of new advanced functional materials. This review offers a comprehensive examination of these materials from five distinct angles. We first discuss their fundamental characteristics and then elaborate on the synthesis methods of crystal hydrogels, categorizing them into three types based on their crystal formation mechanisms. The third section is dedicated to describing the properties of crystal hydrogels. Furthermore, we explore the diverse and remarkable applications that have emerged with the advancement of crystal hydrogels. The review concludes by summarizing the core concepts and assessing the recent opportunities and challenges faced by crystal hydrogels.
Coupling photocatalytic H2 generation with antibiotic degradation offers a promising strategy for addressing energy and environmental challenges, leveraging the synergistic benefits of these processes. Herein, a novel heterojunction photocatalyst consisting of ultrafine CeO2 nanoparticles anchored onto CdS nanosheets was prepared using a simple one-pot in-situ hydrothermal method, enabling the simultaneous photocatalytic H2 generation and tetracycline (TC) degradation. The H2 generation efficiency of the optimal CeO2/CdS (CC-0.10) is 3544 µmol g-1 h-1, which surpasses pure CdS by 29.3 times. Additionally, TC is degraded by CC-0.10 at a rate constant (k value) of 0.0352 min-1, 2.73 times faster than CdS (0.0129 min-1). The free radical quenching and electron spin resonance experiments revealed the active involvement of •OH and •O2- radicals in the TC degradation process. Moreover, the unique CeO2/CdS heterojunction photocatalyst was also effective in degrading TC wastewater with an H2 yield of 1374 µmol g-1 h-1, displaying its dual performance in simultaneously degrading antibiotic wastewater and producing H2. The CeO2/CdS type Ⅱ charge transfer mechanism is confirmed by XPS, EPR, KPFM, fs-TAS, and DFT calculations. This work introduces a promising approach to constructing rare-earth oxide/metal sulfide nanocomposites for addressing the interconnected challenges of energy production and environmental pollution.
Regulating gas diffusion is essential for a range of natural and industrial processes, including underwater breathing, aeration reactor and energy device. Natural organisms, e.g., water boatman, utilize their superaerophilic (SAL) abdomen to create a plastron underwater, enabling efficient gas exchange with dissolved oxygen. Herein, inspired by nature, we have developed a superaerophilic stripe that can form an air film underwater to enhance gas diffusion. Increasing the width (w) of the superaerophilic stripe and height (h) of water, along with decreasing the distance between the bubble and the stripe (d), can improve gas diffusion. Due to the improved dissolved gas diffusion, an efficient hydrogen evolution reaction driven by enhanced H2 diffusion was successfully achieved, resulting in an electrode potential decrease ~13 mV at the same current density of 1 mA/cm2 compared to that without the SAL stripe. This research offers important theoretical insights into the dynamics of gas diffusion and presents practical methods for enhancing gas mass transfer.
Exposure to different neonicotinoid insecticides (NNIs) can cause varying degrees of harm to mammals and may even be carcinogenic. Due to their similar molecular structures, it is not only difficult to distinguish NNIs in analysis, but also cross-reactions can also occur. These cross-reactions cause the calibration curves to exhibit strong nonlinearities that cannot be fitted by usual mathematical models. Here, we present an electrochemical sensor array comprising three sensing units for the simultaneous determination of imidacloprid, thiamethoxam, and nitenpyram. The method eliminates cross-reaction with the aid of machine learning. The machine learning model comprises three components: the Douglas-Peucker algorithm for data compression, principal component analysis for classification, and an artificial neural network for quantification. The randomly assigned validation set showed a classification accuracy of 96.3% for the model. The prediction accuracy was 98.77%. The limit of detection was < 0.037 µmol/L, with a detection range from 0.1 µmol/L to 200 µmol/L. Finally, the spiked tea samples were tested, and a satisfactory agreement was obtained between the expected and predicted values.
In this work, bis-trimethylammonium pillar[5]arene (TP5) was synthesized for ionic pair assembly with 4,4′-biphenyldisulfonic acid (BA) to prepare a new kind of ionic single crystals (TP5-BA). The single crystal structure revealed that TP5-BA adopted an ordered cross-stacked arrangement under the combined influence of electrostatic interactions and π-π stacking forces. It is worth noting that TP5-BA exhibited exceptional performance in the adsorption of iodine vapor, with an adsorption capacity as high as 3.27 g/g. After 6 days, its retention rate remained at a high level of 99.71%. This finding may open up a new direction in supramolecular chemistry with ionic pair self-assembly, not only for the development of novel iodine adsorbent materials but also for many other potential applications such as catalysis and energy.