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The oxygen reduction reaction (ORR) activity of the Fe/N/Carbon catalysts derived from the pyrolysis of zeolitic-imidazolate-framework-8 (ZIF-8) has been still lower than that of commercial Pt-based catalysts utilized in the proton exchange membrane fuel cells (PEMFCs) due to low density of accessible active sites. In this study, an efficient carbon-supporting strategy is developed to enhance the ORR efficiency of the ZIF-derived Fe/N/Carbon catalysts by increasing the accessible active site density. The enhancement lies in (i) improving the accessibility of active sites via converting dodecahedral particles to graphene-like layered materials and (ii) enhancing the density of FeN

The instability of perovskite optoelectronic devices remains a big barrier to their commercialization. The instability caused by external stimuli has been addressed by encapsulation, such as humidity, oxygen, heat, and ultraviolet light. However, the intrinsic instability of perovskite materials due to the lattice strain has not been fully addressed, which affects the physical properties and device performance to a great extent. Tuning the lattice strain by controlling the perovskite composition and ratio is an effective way to further develop efficient and stable devices. Herein, we prepare a series of triple-cation and mixed-halide (FAPbI

The oxide-based all ceramic lithium battery (ACLB) is regarded as one of the safest secondary batteries because it is incombustible and free of toxic gas release. However, high temperature sintering is a necessary step to fabricate the solid-state electrolytes (SSEs) membranes and improve the cathode/SSEs interfacial contact, which bring in high energy consumption as well as the formation of Li-ion resistive interdiffusion phases. Here, we report an in situ coating of lithium-rich antiperovskites (LiRAPs) as sintering aids to solder LiCoO

To develop next-generation electronic devices, novel semiconductive materials are urgently required. The transition metal dichalcogenides (TMDs) hold the promise of next generation of semiconductor materials for emerging electronic applications. As a member of the group-10 TMDs, PdS2 has a notable layer-number-dependent band structure and tremendously high carrier mobility at room temperature. Here, we demonstrate the experimental realization of centimeter-scale synthesis of the few-layer PdS2 by the combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods. For the first time, the optical anisotropic properties of the few-layer PdS2 were investigated through angle-resolved polarized Raman spectroscopy. Also, the evolution of Raman spectra was studied depending on the temperature in the range of 12-300 K. To further understand the electronic properties of the few-layer PdS2, the field-effect transistor (FET) devices were fabricated and investigated. The electronic measurements of such FET devices reveal that the PdS2 materials exhibit a tunable ambipolar transport mechanism with field-effect mobility of up to ∼388 cm2 V-1 s-1 and the on/off ratio of ∼800, which were not reported before in the literature. To well understand the experimental results, the electronic structure of PdS2 was determined using density functional theory (DFT) calculations. These excellent physical properties are very helpful in developing high-performance opto-electronic applications.

The usage of exogenous antioxidant materials to relieve oxidative stress offers an important strategy for the therapy of oxidative stress-induced injuries. However, the fabrication processes toward the antioxidant materials usually require the involvement of extra metal ions and organic agents, as well as sophisticated purification steps, which might cause tremendous environmental stress and induce unpredictable side effects in vivo. To address these issues, herein, we proposed a novel strategy to fabricate green nanoparticles for efficiently modulating oxidative stress, which was facilely prepared from tea polyphenol extracts (originated from green tea) via a green enzymatic polymerization-based chemistry method. The resulting nanoparticles possessed a uniform spherical morphology and good stability in water and biomedium and demonstrated excellent radical scavenging properties. These nanoparticle scavengers could effectively prevent intracellular oxidative damage, accelerate wound recovery, and protect the kidneys from reactive oxygen species damaging in the acute kidney injury model. We hope this work will inspire the further development of more types of green nanoparticles for antioxidant therapies via similar synthetic strategies using green biomass materials.

Intracerebral hemorrhage (ICH) will be accompanied by the overload of iron and reactive oxygen species (ROS) following hematoma clearance. Although deferoxamine (DFO) has been widely utilized as a clinical first-line siderophore to remove the iron overload, the ROS-inducing damage still greatly limits the therapeutic effect of DFO. To address this issue, we designed and fabricated a series of dual-functional macromolecular nanoscavengers featuring high-density DFO units and catechol moieties. Note that the former units could effectively remove the iron overload, while the latter ones could efficiently deplete the ROS. The resulting nanoscavengers efficiently down-regulate the iron and ROS levels as well as significantly reduce the cell death in both iron-overloaded RAW 264.7 cells and the ICH mice model. This work suggests a novel clue for the ICH-ameliorated iron-depleting interventional therapeutic regimen.

The use of natural protein-based thin films has been severely limited because of their relatively low stiffness and strength compared to synthetic polymers. Although the mechanical properties of the protein-based thin films could be enhanced through blending with nanofillers, the fabrication of these materials with nanoscale-to-macroscale hierarchical architecture and robust interfacial adhesion via a facile and green method remains a challenge. Here, we prepared robust protein-based organic/inorganic nanocomposite films with a nacre-like microstructure through directly regulating protein conformation in a simple and biocompatible all-aqueous system. These films contain a high concentration of laponite (Lap) and amyloid-like phase-transited bovine serum albumin (PTB) aggregates rich in β-sheets, which could organize Lap nanoplatelets into an intercalated and multistacked structure. In addition, the PTB aggregates present strong mechanical strength, good stability, and especially superior bioadhesion to afford strong organic/inorganic interface bonding. The resultant PTB/Lap films exhibit high Young's modulus and strength and good chemical stability (in both aqueous solution and organic solvent) and flame retardation, while they are also very transparent (maintaining more than 90% transmittance). Moreover, the film could adhere onto various substrates with robust biomimetic interfacial adhesion, and the resultant coating on glass could function as a smart window to cool down the indoor temperature. Because of their excellent performance and high versatility, the amyloid-like protein/clay nanocomposite films are expected to find broad practical applications.

Fabricating the highly dispersive and stable Pt nanoparticles (NPs) on an economical and environmentally friendly support is of great concern in the field of catalysis. Herein, a waste eggshell was...

Two-dimensional heterojunctions exhibit many unique features in nanoelectronic and optoelectronic devices. However, heterojunction engineering requires a complicated alignment process and some defects are inevitably introduced during material preparation. In this work, a laser scanning technique is used to construct a lateral WSe2 p-n junction. The laser-scanned region shows p-type behavior, and the adjacent region is electrically n-doped with a proper gate voltage. The laser-oxidized product WOx is found to be responsible for this p-type doping. After laser scanning, WSe2 displays a change from ambipolar to unipolar p-type property. A significant photocurrent emerges at the p-n junction. Therefore, a self-powered WSe2 photodetector can be fabricated based on this junction, which presents a large photoswitching ratio of 106, a high photoresponsivity of 800 mA W-1, and a short photoresponse time with long-term stability and reproducibility. Therefore, this selective laser-doping method is prospective in future electronic applications.

Characterizing over-expressed enzymes or biomarkers in living cells is critical for the molecular understanding of disease pathology and consequently for designing precision medicines. Herein, a "switch-on" probe is designed to selectively detect γ-glutamyl transpeptidase (GGT) in living cells via a unique ensemble of enhanced fluorescence and surface-enhanced Raman scattering (SERS). In the presence of GGT, the γ-glutamyl bond in the probe molecule is cleaved, thereby activating a fluorescent probe molecule as well as a Raman reporter molecule. Consequently, the detection of GGT is achieved based on both plasmonic fluorescent enhancement and SERS with a detection limit as low as 1.2 × 10-3 U/L (normal range for GGT levels in the blood is 9-48 U/L). The main advantage of this platform is that on the occasion of fluorescence signal interference, especially in the presence of free metal ions in cells, the SERS signals still hold high stability as a backup. This work highlights the benefits of the marriage of two complimentary sensing techniques into one platform that can overcome the major obstacles of detection of real-time biomarkers and imaging in living cells.

Luminescent liquid crystalline polymers (LLCPs) show extensive application potentials, such as liquid crystal displays and circularly polarized luminescence. In this work, we employ a hydrogen-bonding strategy different from the traditional covalent-bonding method to fabricate LLCPs. First, the acceptor and donor of hydrogen bonding, (4,4′-dibutanoxy tetraphenylethylene)-1-pyridine (PTPEC4) and poly(2-vinyl terephthalic acid) (PPA), respectively, are successfully synthesized. Then, mixtures with different molar ratios (x’s) of PTPEC4 to PPA are used to prepare a series of LLCPs [denoted as PPA(PTPEC4)x]. The resultant LLCPs show a smectic A phase (x ≥ 0.8), a columnar nematic phase (0.6 ≤ x ≤ 0.05), and an amorphous state (x = 0.025), depending on the x value. Meanwhile, all polymers exhibit typical aggregation-induced emission behavior. More interestingly, with the variation of the PTPEC4 content, the series of LLCPs show different colors, that is, the emission peak red shifts from 510 nm (x = 1.0) to 55...

From the conception of atom economy to develop multifunctional nanomaterials, it is important to construct nanomaterials by maximizing functional units while minimizing unnecessary components. Noteworthy, metal-organic framework (MOF) nanoparticles are excellent examples to meet this idea. Current approaches for multifunctional MOFs are mainly based on encapsulation of functional molecules or multistep modification; however, high risk for leakage and burst release and time-consuming and complicated organic synthesis limit their applications. Here, we report a one-pot approach to build the defect structure of a metal organic framework with near-infrared dye (cypate), which is based on the interaction between Fe3+ and carboxyl group of cypate molecules, to construct a multifunctional MOF. Moreover, this system can achieve multimodal imaging guided phototherapy. Subsequently, the precise cancer phototherapy is investigated in vivo, and the tumors are entirely eliminated without obvious side effects, demonstrating the high efficacy and safety of this multifunctional platform. Hence, it is expected that not only this system is simple, safe, and highly effective but also our method of creating defect structures of MOFs will open a new way to develop multifunctional nanoplatforms for bioapplications.

Combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has become a promising cancer treatment in recent years. However, their applications are limited by complex synthetic protocols and low efficacy. Hence, optimizing experimental approach and improving the efficiency of phototherapy is the current research focus. In this work, various pyrolysis temperatures and sizes of zeolitic imidazolate framework-8 (ZIF-8) derived carbon nanoparticles (ZCNs) are obtained by a simple direct pyrolysis of the ZIF-8 nanoparticles. Meanwhile, the ZCNs can be used as photothermal agents and photosensitizers to produce heat and reactive oxygen species simultaneously upon near-infrared laser irradiation. Moreover, it is observed that the phototherapy effects and photoacoustic (PA) signal of ZCNs could be enhanced with the increase in the nanoparticle size. Subsequently, guided by PA imaging, the therapeutic effect of ZCNs is investigated on a small animal model, where tumors are entirely eliminated with minimal side effect, demonstrating the high efficacy of the larger size of ZCNs through combination of PTT and PDT. Therefore, it is expected that the ZCN is a simple and highly effective phototherapeutic platform for oncotherapy, and the concept of size-dependent enhanced behavior of phototherapy and PA imaging will be very useful in the development of nanomaterials for cancer therapy.

As a potent autophagy inducer, Beclin 1 is essential for the initiation of autophagic cell death, and triggering extensive autophagy by targeted delivery of Beclin 1 to tumors has enormous potential to inhibit tumor growth. Yet, the therapeutic application of Beclin 1 is hampered by its inability to internalize into cells and nonselective biodistribution in vivo. To tackle this challenge, we employed a novel Beclin 1 delivery manner by constructing a functional protein (Trx-pHLIP-Beclin 1, TpB) composed of a thioredoxin (Trx) tag, a pH low insertion peptide (pHLIP), and an evolutionarily conserved motif of Beclin 1. This protein could effectively transport Beclin 1 to breast and ovarian cancer cell lines under weakly acidic conditions (pH 6.5), markedly inhibit tumor cell growth and proliferation, and induce obvious autophagy. Furthermore, the in vivo antitumor efficacy of the functional Beclin 1 against an SKOV3 xenograft tumor mouse model was tested via intravenous injection. TpB preferentially accumulated in tumors and exhibited a significantly higher tumor growth inhibition than the nontargeted Beclin 1 control, whereas no overt side effects were observed. Taken together, this study sheds light on the potential application of TpB as a highly efficient yet safe antitumor agent for cancer treatment.

Lymph node (LN) status is a major indicator of stage and survival of lung cancer patients. LN dissection is a primary option for lung cancer LN metastasis; however, this strategy elicits adverse effects and great trauma. Therefore, developing a minimally invasive technique to cure LN metastasis of lung cancer is desired. In this study, multiwalled carbon nanotubes (MWNTs) coated with manganese oxide (MnO) and polyethylene glycol (PEG) (namely MWNTs-MnO-PEG) was employed as a lymphatic theranostic agent to diagnose and treat metastatic LNs. After single local injection and lymph drainage were performed, regional LNs were clearly mapped by T1-weighted magnetic resonance (MR) of MnO and dark dye imaging of MWNTs. Meanwhile, metastatic LNs could be simultaneously ablated by near-infrared (NIR) irradiation under the guidance of dual-modality mapping. The excellent result was obtained in mice bearing LNs metastasis models, showing that MWNTs-MnO-PEG as a multifunctional theranostic agent was competent for dual-modality mapping guided photothermal therapy of metastatic LNs.

Electrocatalytic reactions of glucose oxidation based on enzyme-labeled electrochemical biosensors demand a high enzymatic activity and fast electron transfer property to produce the amplified signal response. Through a "green" synthesis method, Pt@BSA nanocomposite was prepared as a biosensing interface for the first time. Herein we presented a convenient and effective glucose sensing matrix based on Pt@BSA nanocomposite along with the covalent adsorption of glucose oxidase (GOD). The electrocatalytic activity toward oxygen reduction was significantly enhanced due to the excellent bioactivity of anchored GOD and superior catalytic performance of interior platinum nanoparticles, which was gradually restrained with the addition of glucose. A sensitive glucose biosensor was then successfully developed upon the restrained oxygen reduction peak current. Differential pulse voltammetry (DPV) was employed to investigate the determination performance of the enzyme biosensor, resulting in a linear response range from 0.05 to 12.05 mM with an optimal detection limit of 0.015 mM. The as-proposed sensing technique revealed high selectivity against endogenous interfering species, satisfactory storage stability, acceptable durability, and favorable fabrication reproducibility with the RSD of 3.8%. During the practical application in human blood serum samples, this glucose biosensor obtained a good detection accuracy of analytical recoveries within 97.5 to 104.0%, providing an alternative scheme for glucose level assay in clinical application.

Mesoporous magnetic supraparticles (meso-MSPs) as multifunctional targeted drug carriers have attracted much attention, because of their easy magnetic-field manipulation and in situ sensing functionality. In this paper, a Fe(3+)-selective chemodosimeter fluorescent probe (FP-1) was synthesized and loaded inside of the meso-MSPs (meso-MSPs/probe); the meso-MSPs/probe nanocomposites were then used to monitor the degradation of meso-MSPs in cells. In our experiments, strong fluorescence intensity was observed in HeLa cells, because of their acidic intracellular environment, which can quickly degrade the meso-MSPs and then release Fe(3+) ions in cells that, in turn, activate the fluorescence of FP-1. Meanwhile, a very weak fluorescence signal was detected in HEK 293T cells due to the relative neutral intracellular environment of HEK 293T cells, which prevented the Fe(3+) ion from leaching out of meso-MSPs. Moreover, this degradation-luminescence relationship of the meso-MSPs/probe nanocomposites not only assisted us to understand the degradation status of meso-MSPs in cells, but also allowed us to recognize the peculiarity of different cells with various intracellular environments.

Through combined application of wormlike-micelle and rod-coating technique, a general method was demonstrated for the facile reparation of thin transparent conductive films (TCF) of various nanomaterials and their hybrids on flexible plastics. The cetyltrimethylammonium hydroxide (CTAOH)/p-toluenesulfonic acid (CTAT) wormlike micelle system was selected for both the dispersion of different nanomaterials and the enhancement of viscosities of the coating fluids. With the single-walled carbon nanotubes (SWNTs)/wormlike micelle aqueous dispersions as coating fluid, TCFs of SWNTs on flexible poly(ethylene terephthalate) (PET) substrates made by rod-coating method were demonstrated. After doping by immersion into thionyl chloride solution, the sheet resistance of SWNTs thin films, which had a transmittance of about 78%, was as low as 480Ω/sq. This coating method was extended to the preparation of thin films or networks of other materials such as reduced graphene oxide and Ag nanowires. The obtained TCF from Ag nanowire networks has a low sheet resistance of 17Ω/sq, which is comparable to the value of best indium tin oxide (ITO) coating on plastic substrates. Finally, hybrid thin films of different nanomaterials were demonstrated by this method.