High concentration of arsenic in acid wastewater and polluted river sediment caused by metallurgical industry has presented a great environmental challenge for decades. Nanoscale zero valent iron ...(nZVI) can detoxify arsenic-bearing wastewater and groundwater, but the low adsorption capacity and rapid passivation restrict its large-scale application. This study proposed a highly efficient arsenic treatment nanotechnology, using the core-shell Fe@Fe2O3 nanobunches (NBZI) for removal of arsenic in acid wastewater with cyclic stability and transformation of arsenic speciation in sediment. The adsorption capacity of As(III) by NBZI was 60 times as high as that of nanoscale zero valent iron (nZVI) at neutral pH. Characterization of the prepared materials after reaction revealed that the contents of As(III) and As(V) were 65% and 35% under aerobic conditions, respectively, which is the evidence of oxidation included in the reaction process apart from adsorption and co-precipitation. The presence of oxygen was proved to improve the adsorption ability of the prepared NBZI towards As(III) with the removal efficiency increasing from 68% to 92%. In order to further enhance the performance of NBZI-2 in the absence of oxygen, a new Fenton-Like system of NBZI/H2O2 to remove arsenic under the anoxic condition was also proposed. Furthermore, the removal efficiency of arsenic in acid wastewater remained to be 78% after 9 times of cycling. Meanwhile, most of the mobile fraction of arsenic in river sediment was transformed into residues after NBZI treatment for 20 days. The reaction mechanism between NBZI and arsenic was discussed in detail at last, indicating great potential of NBZI for the treatment of arsenic in wastewater and sediment.
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•The Fe@Fe2O3 nanobunches (NBZI) presents high removal capacity of arsenic in acid wastewater.•Aerobic NBZI system possesses better stability in acid wastewater than anoxic system.•NBZI possesses strong ability to stabilize arsenic in sediment.•Removal pathways of arsenic under aerobic or anoxic conditions were proposed.
This work reports a facile and sensitive self-powered cathodic photoelectrochemical (PEC) aptasensor for the detection of oxytetracycline (OTC) based on Au nanoparticles-decorated phosphorus-doped ...porous ultrathin g-C3N4 nanosheets (Au/PCN-S). The prepared PCN-S possesses large specific surface area with abundant in-plane pores on its surface, ideal biocompatibility, and excellent visible light response. The in situ photo-reduced Au nanoparticles further enhanced the PEC performance owing to its unique surface plasmon resonance (SPR) effect. Under visible light irradiation, the photocurrent of Au/PCN-S composites was significantly enhanced, which was about 22 times higher than that of pure g-C3N4. In the self-powered PEC biosensing of OTC, the device exhibited high sensitivity toward the presence of dissolved oxygen in the electrolyte and presented a wide detection range from 0.5 to 200 nM and a detection limit of 0.34 nM, as well as certain selectivity, reproducibility and stability. The proposed Au/PCN-S nanocomposites would be considered as a promising visible light-responsive photoactive material for fabrication of PEC biosensors with high performance.
•Au-decorated p-doped porous ultrathin g-C3N4 nanosheets (Au/PCN-S) were prepared.•P doping and SPR effect significantly improved optical performance of Au/PCN-S..•Porous and ultrathin structure can increase the specific surface area of Au/PCN-S.•The self-powered PEC aptasensing of OTC at bias potential of 0 V was realized.
A low-cost semiconductor-based photocatalyst using visible light energy has attracted increasing interest for energy generation and environmental remediation. Herein, plasmonic Bi metal was deposited ...in situ in g-C3N4@Bi2WO6 microspheres via a hydrothermal method. As an electron-conduction bridge, metallic Bi was inserted as the interlayer between g-C3N4 and the surface of Bi2WO6 microspheres to enhance visible light absorption due to the surface plasmon resonance (SPR) effect and facilitate efficient electron-carrier separation. Different characterization techniques, including XRD, SEM, TEM, UV–vis, XPS, photoluminescence, and photocurrent generation, were employed to investigate the morphology and optical properties of the as-prepared samples. The results indicated that the g-C3N4(20%)@Bi@Bi2WO6 microsphere sample exhibited an extraordinary enhanced photocatalytic activity, higher than those of the g-C3N4, Bi2WO6, and g-C3N4(20%)@Bi2WO6 samples. It implies that the heterostructured combination of g-C3N4, metallic Bi, and Bi2WO6 microspheres provided synergistic photocatalytic activity via an efficient electron transfer process. On the basis of the results, a possible photocatalytic mechanism of the as-prepared samples was proposed. The present study demonstrated the feasibility of utilizing low-cost metallic Bi as a substitute for noble metals to design a doped photocatalysis composite with enhanced photocatalytic performance.
Anoctamin 1 (ANO1) or TMEM16A gene encodes a member of Ca2+ activated Cl– channels (CaCCs) that are critical for physiological functions, such as epithelial secretion, smooth muscle contraction and ...sensory signal transduction. The attraction and interest in ANO1/TMEM16A arise from a decade long investigations that abnormal expression or dysfunction of ANO1 is involved in many pathological phenotypes and diseases, including asthma, neuropathic pain, hypertension and cancer. However, the lack of specific modulators of ANO1 has impeded the efforts to validate ANO1 as a therapeutic target. This review focuses on the recent progress made in understanding of the pathophysiological functions of CaCC ANO1 and the current modulators used as pharmacological tools, hopefully illustrating a broad spectrum of ANO1 channelopathy and a path forward for this target validation.
The abnormal expression or dysfunction of Ca2+ activated Cl– channel anoctamin 1 (ANO1) is involved in pathological phenotypes and diseases, suggesting that pharmacological modulation of ANO1 may serve as therapeutic potential and strategy. Display omitted
Exploring stable two-dimensional materials with appropriate band gaps and high carrier mobility is highly desirable due to the potential applications in optoelectronic devices. Here, the electronic ...structures of phosphorene on a Au(111) substrate are investigated by scanning tunneling spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations. The substrate-induced phosphorene superstructure gives a superlattice potential, leading to a strong band folding effect of the sp band of Au(111) on the band structure. The band gap could be clearly identified in the ARPES results after examining the folded sp band. The value of the energy gap (∼1.1 eV) and the high charge carrier mobility comparable to that of black phosphorus, which is engineered by the tensile strain, are revealed by the combination of ARPES results and DFT calculations. Furthermore, the phosphorene layer on the Au(111) surface displays high surface inertness, leading to the absence of multilayer phosphorene. All these results suggest that the phosphorene on Au(111) could be a promising candidate, not only for fundamental research but also for nanoelectronic and optoelectronic applications.
Quantum-sized cerium dioxide (CeO2) show high catalytic capability as well as strong light absorption ability owing to its redox couple Ce4+/Ce3+ and abundant oxygen vacancies, which making it a ...potential material for designing superior photoelectrochemical (PEC) sensors. However, it has scarcely been applied in the field of PEC sensing, because its wide band gap and aggregation effect can restrict the photoelectric conversion efficiency. Herein, we address these two obstacles by coupling CeO2 quantum dots (QDs) with graphitic carbon nitride (g-CN) and Au nanoparticles (NPs). The electron transfer path in this proposed heterojunction was proved by density functional theory (DFT) calculation for the first time, which provided theoretical support for the detection of MC-LR. The as-obtained PEC aptasensor exhibited excellent analytical performance with a wide liner response of 0.05–105 pM, and the detection limit was 0.01 pM. By designing appropriate sensing system and specific recognition mechanism, this work may pave a unique avenue for constructing ultrasensitive and selective analysis of MC-LR in complex environment without any external electric source.
•CeO2 was first applied in PEC sensing by designing an ACG heterostructure.•The electron transfer process in ACG heterostructure was proved by DFT calculation.•The specific recognition mechanism of aptamers makes this sensor more selective.•The accurate measurement of MC-LR in water samples by this sensor was obtained.
Atherosclerosis (AS), a chronic arterial disease, is the leading cause of death in western developed countries. Considering its long-term asymptomatic progression and serious complications, the early ...prevention and effective treatment of AS are particularly important. The unique characteristics of nanoparticles (NPs) make them attractive in novel therapeutic and diagnostic applications, providing new options for the treatment of AS. With the assistance of reactive oxygen species (ROS)-based NPs, drugs can reach specific lesion areas, prolong the therapeutic effect, achieve targeted controlled release and reduce adverse side effects. In this article, we reviewed the mechanism of AS and the generation and removal strategy of ROS. We further discussed ROS-based NPs, and summarized their biomedical applications in scavenger and drug delivery. Furthermore, we highlighted the recent advances, challenges and future perspectives of ROS-based NPs for treating AS.
Ultrasound with low frequency (20-100 kHz) assisted drug delivery has been widely investigated as a non-invasive method to enhance the permeability and retention effect of drugs. The functional ...micro/nanobubble loaded with drugs could provide an unprecedented opportunity for targeted delivery. Then, ultrasound with higher intensity would locally burst bubbles and release agents, thus avoiding side effects associated with systemic administration. Furthermore, ultrasound-mediated destruction of micro/nanobubbles can effectively increase the permeability of vascular membranes and cell membranes, thereby not only increasing the distribution concentration of drugs in the interstitial space of target tissues but also promoting the penetration of drugs through cell membranes into the cytoplasm. These advancements have transformed ultrasound from a purely diagnostic utility into a promising theragnostic tool. In this review, we first discuss the structure and generation of micro/nanobubbles. Second, ultrasound parameters and mechanisms of therapeutic delivery are discussed. Third, potential biomedical applications of micro/nanobubble-assisted ultrasound are summarized. Finally, we discuss the challenges and future directions of ultrasound combined with micro/nanobubbles.
Glioblastoma (GBM) is the most aggressive brain tumor, which owns the characteristics of high recurrence, low survival rate and poor prognosis because of the existence of blood brain barrier (BBB) ...and complicated brain tumor microenvironment. Currently, immunotherapy has attracted much attention on account of favorable therapeutic effect. In this study, we designed a cRGD-modified cancer cell membrane (CM) coated calcium carbonate nanoparticle to deliver interleukin-12 messenger RNA (IL-12 mRNA@cRGD-CM-CaCO
NPs). The cRGD-modified CM as the shell can endow the nanoparticles with BBB crossing and tumor homing/homotypic targeting effect in the brain tumor microenvironment. IL-12 mRNA-loaded calcium carbonate nanoparticles as the core allow synergistic immunotherapy of necroptosis-induced immune response and IL-12 mRNA transfection under ultrasound irradiation. The as-prepared biomimetic nanoparticles showed superior target and immunotherapeutic outcomes, suggesting that this biomimetic nanoplatform provides a feasible strategy for promoting BBB-penetrating and antitumor immunity.
With the development of nanomedicine technology, stimuli-responsive nanocarriers play an increasingly important role in antitumor therapy. Compared with the normal physiological environment, the ...tumor microenvironment (TME) possesses several unique properties, including acidity, high glutathione (GSH) concentration, hypoxia, over-expressed enzymes and excessive reactive oxygen species (ROS), which are closely related to the occurrence and development of tumors. However, on the other hand, these properties could also be harnessed for smart drug delivery systems to release drugs specifically in tumor tissues. Stimuli-responsive nanoparticles (srNPs) can maintain stability at physiological conditions, while they could be triggered rapidly to release drugs by specific stimuli to prolong blood circulation and enhance cancer cellular uptake, thus achieving excellent therapeutic performance and improved biosafety. This review focuses on the design of srNPs based on several stimuli in the TME for the delivery of antitumor drugs. In addition, the challenges and prospects for the development of srNPs are discussed, which can possibly inspire researchers to develop srNPs for clinical applications in the future.
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