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Nb2O5 is a colourless metal oxide that is very promising in areas such as energy storage and optical glasses. These applications depend on the superior redox properties of Nb2O5 compared to those of other metal oxides, which in turn endow it with great potential in semiconductor photocatalysis. Herein, a hierarchical Nb2O5 was synthesized by the L -arginine-assisted hydrothermal method. Thereafter, visible light photocatalysis was bridged over hierarchical Nb2O5 with a common organic dye, namely alizarin red S (ARS), significantly renovating Nb2O5-based photocatalysis from ultraviolet (UV) into the green light region. The surface of hierarchical Nb2O5 was chemically modified with ARS to harvest 520 nm green light and facilitate the oxidation of organic sulfides with aerial O2. The O-atom transfer from O2 into sulfoxides with very high selectivity occurs via an intermediate of superoxide radical anions (O2˙−). Importantly, the electron transfer from activated ARS to sulfides is mediated by an electron transfer mediator, namely (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), to deter the attack of quenched ARS by reactive oxygen species (ROS). This study represents the first foray of dye-semiconductor assemblies based on a semiconductor other than TiO2 for the selective aerobic oxidation, affirming the generality of cooperative photocatalysis and implying the great potential of hierarchical Nb2O5 in platforming the visible-light-induced selective transformation of organic molecules. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a heavy metal with high toxicity and easy migration; it can be enriched through the food chain, and cause serious threats to the natural environment and human health. So, the development of a method that can be used to detect mercury ions (Hg2+) in the environment, in cells, and in organisms is very important. Here, a new 7‐hydroxycoumarin‐derived carbonothioate‐based probe (CC‐Hg) was designed and synthesized for detection of Hg2+. After addition of Hg2+, a large fluorescence enhancement was observed due to the formation of 7‐hydroxyl, which reinforced the intramolecular charge transfer process. The CC‐Hg probe had good water solubility and selectivity. Moreover, the probe was able to detect Hg2+ quantitatively over the concentration range 0–2 μM and with a detection limit of 7.9 nM. Importantly, we successfully applied the probe to detect Hg2+ in water samples, in living cells, and in zebrafish. The experimental results demonstrated its potential value in practical applications. [ABSTRACT FROM AUTHOR]

We have synthesized a simple Golgi-targeting H2S fluorescent probe which can detect endogenous and exogenous H2S in cells and zebrafish. In addition, this probe provides a new chemical tool for the detailed study of generation pathways of H2S under Golgi stress response. [ABSTRACT FROM AUTHOR]

Neuropeptide Y (NPY) is a significant neuromodulator implicated in a multitude of physiological functions via activating NPY receptors which belong to seven transmembrane G-protein-coupled receptors (GPCRs). However, the detailed cellular expression of NPY receptors in retina has been scarcely investigated. In this study, the expression of the special NPY4R receptor in rat retina was assessed using Western blot analysis and immunofluorescent staining. The detailed cellular localization of NPY4R receptor was studied using double immunofluorescent staining and laser-scanning confocal microscopy. Our data demonstrated that NPY4R receptor was weakly expressed in the inner segment of outer photoreceptors and extensively expressed in the outer segment of S-opsin-positive blue cones, L/M-opsin-positive red/green cones and in the somata of CB-positive horizontal cells, GAD65-positive GABAnergic amacrine cells, ChAT-positive cholinergic amacrine cells, TH-positive dopaminergic CA1 amacrine cells and CA2 amacrine cells, PV-positive AII amacrine cells, Brn3a-positive conventional ganglion cells and melanopsin-containing ipRGCs. In addition, NPY4R receptor was diffusely distributed throughout the full thickness of the inner plexiform layer and outer plexiform layer. However, the outer segment of Rho4D2-positive rods, the somata of ChX10-positive bipolar cells and CRALBP-positive Müller glial cells seemed to lack immunoreactivity of NPY4R receptor. The new finding that multiple types of retinal cell express NPY4R receptor provides new neurobiological basis for the participation of NPY in the regulation of retinal functions through activating NPY4R receptor. [Display omitted] [ABSTRACT FROM AUTHOR]

This study designed a pH-sensitive nanogel based on sodium alginate and chitosan. In order to improve the solubility of chitosan and reduce the toxicity caused by crosslinking agent, a specific synthetic pathway was designed. Structural modification of chitosan with various hydroxypropyl and carboxyl groups afforded a chitosan derivative (CHPCS), which was mixed with the oxidized sodium alginate (AO) to provide the desired sodium alginate-chitosan nanogel (AO/CHPCS-NG). Morphology study indicated that the nanogel had spherical shape with average diameter of 40–50 nm. Berberine (BBR) was used as the model drug for drug loading study, which produced BBR-loaded nanogel (AO/CHPCS-NG-BBR) with pH-sensitive release ability in vitro. Cytotoxicity investigation showed that AO/CHPCS-NG-BBR had no obvious effect on proliferation of human umbilical vein endothelial cells (HUVECs), which proved its low toxicity on normal human cells. In contrast, AO/CHPCS-NG-BBR exhibited high toxicity against human hepatoma cells (HepG2), thus confirming that the synthesized nanogel should be a potential drug carrier and had widespread applications. [ABSTRACT FROM AUTHOR]

With permanent porosity and intrinsic crystallinity, covalent organic frameworks (COFs) have great potential for solar energy conversions. However, the crystallinity of COFs necessitates reversible linkages like imine, leading to inadequate chemical stability of COFs as photocatalysts. To overcome this inadequacy, post-synthetic modifications (PSMs) transform an imine-linked COF, TTI-COF, into a thiazole-linked COF, TTT-COF. The morphology and crystallinity of TTT-COF are similar to that of TTI-COF. Compared to TTI-COF, TTT-COF secures evident amelioration of stability and optoelectronic properties supported by both experiments and theoretical calculations. Consequently, these two COFs are exploited for the photocatalytic oxidation of organic sulfides. Under blue light-emitting diode irradiation, TTI-COF marginally impels the reaction. In contrast, TTT-COF emerges with significantly better activity for selective oxidation of organic sulfides with oxygen in ethanol. This work sheds light on the transformative power of PSMs for tailoring COFs in visible light photocatalysis for oxidations. [Display omitted] • TTT-COF is successfully transformed from TTI-COF through PSMs. • The morphology and crystallinity of TTT-COF are similar to that of TTI-COF. • TTT-COF ameliorates stability and optoelectronic properties. • TTT-COF is superior to TTI-COF for blue light photocatalysis. • Organic sulfides are oxidized to corresponding sulfoxides over TTT-COF. [ABSTRACT FROM AUTHOR]

[Display omitted] • The probe owns high specificity in response to hydrogen peroxide. • The probe is proved with good biosafety using 8 types of detection techniques. • The probe can sensitively detect hydrogen peroxide in cells and zebrafish. As one of the most widely distributed reactive oxygen species in vivo, hydrogen peroxide plays divergent and important roles in cell growth, differentiation and aging. When the level of hydrogen peroxide in the body is abnormal, it will lead to genome mutation and induce irreversible oxidative modification of proteins, lipids and polysaccharides, resulting in cell death or even disease. Therefore, it is significant to develop a sensitive and specific probe for real-time detection of hydrogen peroxide in vivo. In this study, the response mechanism between hydrogen peroxide and probe QH was investigated by means of HRMS and the probe showed good optical properties and high selectivity to hydrogen peroxide. Note that the evaluating of probe biocompatibility resulted from cytotoxicity test, behavioral test, hepatotoxicity test, cardiotoxicity test, blood vessel toxicity test, immunotoxicity test and neurotoxicity test using cell and transgenic zebrafish models with more than 20 toxic indices. Furthermore, the detection performance of the probe for hydrogen peroxide was evaluated by multiple biological models and the probe was proved to be much essential for the monitoring of hydrogen peroxide in vivo. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H 2 O 2), as one of reactive oxygen species (ROS) widely present in the human body, is involved in a variety of physiological activities. Many human diseases are associated with abnormal levels of H 2 O 2 in the body. Mitochondria are the main organelles producing H 2 O 2 in the human body, and monitoring the level of H 2 O 2 in mitochondria can help to deepen the understanding of the detailed functions of H 2 O 2 in physiological activities. However, due to the highly dynamic nature of the cells, real-time quantitative monitoring of H 2 O 2 levels in mitochondria remains an ongoing challenge. Herein, a novel highly immobilized mitochondria-targeting fluorescent probe (QHCl) for detection of H 2 O 2 was reasonably constructed based on quinolinium dye containing benzyl chloride moiety. Spectral experimental results demonstrated QHCl possessed outstanding selectivity toward H 2 O 2 (λ ex/em = 380/513 nm). In addition, QHCl can quantitatively detect H 2 O 2 in the concentration range of 0–20 μM with excellent sensitivity (LOD = 0.58 μM) under the PBS buffer solution (10 mM, pH = 7.4). Finally, bioimaging experiments demonstrated that the probe QHCl was able to be used for accurately detecting both endogenous and exogenous H 2 O 2 in the mitochondria of living cells and zebrafish by its unique mitochondrial immobilization. [Display omitted] • Probe can achieve highly immobilized monitoring of H 2 O 2 in mitochondria. • Probe has excellent water-solubility and high sensitivity for H 2 O 2 detection. • Probe exhibited preeminent selectivity towards H 2 O 2 over other reactive oxygen species. • Probe can realize in situ detection of H 2 O 2 in live cells and zebrafish. [ABSTRACT FROM AUTHOR]

As an essential reactive oxygen species (ROS), hypobromous acid (HOBr) plays a vital role in the immune process. Nevertheless, excessive HOBr can cause a series of diseases including cancers. Therefore, the development of the in situ detection methods for intracellular HOBr in biosystems is urgent and important to further uncover the detailed physiological and pathological effects of HOBr. In this work, a simple water-soluble near-infrared (NIR) fluorescence dye was synthesized, which was satisfactory chosen as a highly selective and sensitive fluorescent probe for the rapid detection of HOBr based on the electrophilic bromination reaction mechanism. This probe can perform the specific detection of HOBr, which facilitates the accurate imaging of HOBr in biosystems. Finally, this probe was successfully applied to trace mitochondrial HOBr fluctuations with high resolution in living cells and zebrafish. [Display omitted] • A simple water-soluble NIR fluorescence dye was synthesized. • Probe CSDA achieved the specific detection of HOBr based on the electrophilic bromination reaction mechanism. • Probe CSDA performed rapid and sensitive detection of HOBr with NIR emission wavelength. • Probe CSDA was used to detect mitochondrial HOBr fluctuations in living cells and zebrafish. [ABSTRACT FROM AUTHOR]