Here we report a new rhodamine-based fluorescent probe containing a selenium−nitrogen bond for detecting thiols based on the nucleophilic substitution of sulfhydryl. The probe was successfully applied to the imaging of thiols in both HL-7702 cells and HepG2 cells with high sensitivity and selectivity.

Ultrasmall Ni2P/rGO was synthesized using template-confinement strategy of MOFs and served as a highly efficient electrocatalyst for overall water splitting.

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A novel nanoporous metal−organic framework NPC-4 with excellent thermal stability was assembled from 2,3,5,6-tetramethylbenzene-1,4-diisophthalate (TMBDI) and the paddle-wheel secondary building unit (Cu 2 (COO) 4 ). The porous structure comprises a single type of nanoscale cage (16 Å diameter) interconnected by windows (5.2 × 6.3 Å), which give a high pore volume. CH 4 (195−290 K), CO 2 (198−303 K), N 2 (77 K), and H 2 (77 K) adsorption isotherms were studied for pressures up to 20 bar. NPC-4 exhibits excellent methane and carbon dioxide storage capacities on a volume basis with very high adsorbate densities, under ambient conditions. Isobars were investigated to establish the relationship for adsorption capacities over a range of storage temperatures. The isosteric enthalpies of adsorption for both CH 4 and CO 2 adsorption did not vary significantly with amount adsorbed and were ∼15 and ∼25 kJ mol −1 , respectively. The adsorption/desorption kinetics for CH 4 and CO 2 were investigated and activation energies, enthalpies of activation, and diffusion parameters determined using various kinetic models. The activation energies for adsorption obtained over a range of uptakes from the stretched exponential kinetic model were 5.1− 6.3 kJ mol −1 (2−13.5 mmol g −1 ) for CO 2 and 2.7−5.6 kJ mol −1 (2−9 mmol g −1 ) for CH 4 . The activation energies for surface barriers and diffusion along pores for both CH 4 and CO 2 adsorption obtained from a combined barrier resistance diffusion model did not vary markedly with amount adsorbed and were <9 kJ mol −1 . Comparison of kinetic and thermodynamic parameters for CH 4 and CO 2 indicates that a surface barrier is rate determining at high uptakes, while intraparticle diffusion involving diffusion through pores, consisting of narrow windows interconnecting with nanocages, being rate determining at very low uptakes. The faster CH 4 intraparticle adsorption kinetics compared with CO 2 for NPC-4 was attributed to faster surface diffusion due to the lower isosteric enthalpy of adsorption for CH 4 .

Understanding the crystallization pathway is of fundamental importance in controlling structures and functionalities for metal–organic frameworks (MOFs), but only few studies have been reported on the mechanism of crystallization for MOFs to date. Here, by using a microdroplet flow (MF) reaction technique, we successfully revealed the different status of HKUST-1 during its crystal growth process. The morphologies and structures of crystals at different stages were recorded and characterized by scanning electron microscopy, transmission electron microscopy, and small-angle X-ray diffraction. Experimental observations clearly demonstrate a process of crystallization by particle attachment (CPA) for crystal growth of HKUST-1 under MF conditions. The superstructure of HKUST-1, which is assembled from oriented attachment of nanosized particles of HKUST-1, is observed at early stage of crystal growth. This type of superstructure gradually transforms to true single crystals through a ripening effect upon increasing residence time, accompanied by increase in dimensions of crystals. Thus, the superstructure is the intermediate state during crystallization and acts as the bridge between disordered reactants and highly ordered single crystals. Based on these findings, the crystal growth of HKUST-1 in MF reaction can be elucidated as a process involving three steps: the generation of nanosized primary particles, the following assembly of the primary particles into a superstructure, and the ripening of superstructure into a crystal. Furthermore, the superstructure of HKUST-1 shows superior performance for CO2 and CH4 adsorptions. The CPA mechanism in the crystallization of HKUST-1 demonstrated in this work is in clear contrast to the monomer-by-monomer addition mechanism in classic models of crystal growth. This mechanism could have important reference meaning for understanding the crystal growth mechanism of other type of MOFs or other special morphologies.

Pulmonary fibrosis is a fatal chronic lung disease, leading to poor prognosis and high mortality. Accumulating evidence suggests that oxidative stress characterized by excessive production of hydrogen peroxide (H 2 O 2 ) is an important molecular mechanism causing pulmonary fibrosis. We conceive a new type of mitochondria-targeted near-infrared fluorescent probe Mito-Bor to investigate changes in the level of endogenous H 2 O 2 in living cells and mice models with pulmonary fibrosis. In the design strategy of the Mito-Bor probe, we selected azo-BODIPY as the fluorophore owing to its near-infrared fluorescence, strong photochemical stability, and low biological toxicity. Under physiological conditions, the response moiety 4-bromomethylphenylboronic acid pinacol ester could easily detect H 2 O 2 , and turn the fluorescence switch on. The modification of the lipophilic triphenylphosphine cation on the fluorophore would allow the probe to easily pass through the phospholipid bilayer of cells, and the internal positive charge could contribute to the selectivity of the mitochondria accumulation. The Mito-Bor probe provides high selectivity, low limit of detection, high biocompatibility, and excellent photostability. It can be used to detect changes in the level of H 2 O 2 in living cells and in vivo. Therefore, the probe is applied to investigate the fluctuation of the H 2 O 2 level during the process of inducing pulmonary fibrosis in cells, with changes in its fluorescence intensity correlating with the concentration of H 2 O 2 and indicating the level of oxidative stress in fibroblasts. Conversely, pulmonary fibrosis can be modulated by adjusting the level of H 2 O 2 in cells. A further study in mice models of bleomycin-induced pulmonary fibrosis confirms that NADPH oxidase 4 (NOX4) acts as a "button" to regulate H 2 O 2 levels. The direct inhibition of NOX4 can significantly reduce the level of H 2 O 2 , which can delay the progression of lung fibrosis. These results provide an innovative way for the clinical treatment of pulmonary fibrosis.

As the most abundant nonprotein biothiol in living cells, glutathione (GSH) prevents cellular components from oxidative damage and maintains the intracellular redox homeostasis. For further exploring whether GSH can be employed as a bioindicator to discriminate tumor lesion at a cellular level, the highly selective detection and accurate quantification of GSH under pathological conditions are critical. Herein, we design a coumarin derivative-based two-photon fluorescent probe Cou-Br for the detection of GSH in living cells, mice models, and clinical specimens. The prepared probe is capable of sensitively and selectively detecting GSH in complex biological systems. Cou-Br displays a good linear relationship in response to GSH and a low limit of detection. With the fluorescence signal positively associated with intracellular GSH levels, the probe enables real-time imaging of GSH in various cell lines. Under the condition of CS 2 stimulation, Cou-Br can rapidly respond to the fluctuation of intracellular GSH induced by oxidative damage. Furthermore, the in situ and in vivo bioimaging performances of Cou-Br are demonstrated. Typically, relying on the different cellular concentrations of GSH, the probe is successfully employed to identify the human laryngeal cancer lesion with outstanding capabilities of deep tissue imaging and tumor margin recognition. We assume that the abnormal expression level of GSH may be utilized as a potential bioindicator to discriminate tumor tissues from the surrounding disease-free tissues. To conclude, the proposed probe Cou-Br may potentially serve as a powerful chemical tool for the surgical navigation of cancer in clinic.

Following the wisdom of nature to assemble functional candidates into exquisite nanoarchitectures is emerging as a promising field of research and has been widely applied in biomedical sciences. Owing to their excellent properties of structural controllability, functional diversity, dynamic adjustability, and prominent biocompatibility, the self-assembled nanoarchitectures come to play a pivotal role in fighting against cancer. This review outlines the most up-to-date developments in constructing phototherapeutic nanomaterials for photodynamic and photothermal therapy (PDT and PTT) of tumors, with emphasis on design ideas, building blocks, and advantageous characteristics of self-assembly. The prominent activities of cancer therapy obtained by these photoinduced nanotheranostics are also explored in-depth, together with the connections between the specific nanostructures and unique features, providing a comprehensive understanding of the self-assembled nanomaterials in improving the outcomes of PDT and PTT. This review aims to highlight the significance of self-assembled nanomaterials in enhancing phototherapeutic efficacy and to promote its development in various research interests ranging from material science and nanoscience to biomedicine and clinical medicine.