查找使用阿拉丁产品的科研文献

Construction of BaTiO3/CeO2 heterojunction and comparative study on photocatalytic activity of degradation of different drugs

Ye Chao,Li Chengui

A type II band aligned BaTiO3/CeO2 photocatalysts was constructed by a simple one-step solution synthesis method. The BaTiO3/CeO2 photocatalysts contain only cubic phase BaTiO3 and CeO2, and the particles are approximately spherical with a small amount of adhesion and agglomeration, and the average particle size is about 50 nm. Transmission electron microscopy (TEM) observation and element Mapping characterization confirmed the formation of special heterojunction between BaTiO3 and CeO2 and the presence of a large number of oxygen vacancies, which resulted in high visible optical absorption coefficient. The BaTiO3/CeO2 photocatalysts demonstrated high photocatalytic activity for the degradation of oxytetracycin hydrochloride, and the optimal drug concentration, catalyst content and pH value are 50 mg/L, 1 g/L and 7, respectively. Simultaneously, the BaTiO3/CeO2 photocatalysts were selective for degradation of aureomycin hydrochloride, doxycycline hydrochloride and tetracycline hydrochloride. Other photocatalytic experiments show that the BaTiO3/CeO2 photocatalysts have high chemical and cyclic stability, and the synergistic effect of holes, hydroxyl radicals and superoxide radicals plays an important role in the whole photocatalytic process. This simple synthesis route provides a technical reference for constructing other wide-band gap semiconductors to respond to simulated sunlight.

An NIR light-responsive “on-off-on” photoelectrochemical aptasensor for carcinoembryonic antigen assay based on Y-shaped DNA

Bo Liu,Yonghao Ge,Yahui Lu,Yibo Huang,Xiaoru Zhang,Xunyi Yuan

This work develops a novel photoelectrochemical sensor for the detection of carcinoembryonic antigen (CEA) based on the composite of UCNPs with semiconductors and conformational changes in the DNA structure . Firstly, SnS 2 , ZnIn 2 S 4 and UCNPs were assembled on the surface of the ITO electrode. Then Au NPs were dropped, which could facilitate the coupling of CdSe NPs modified DNA1 via Au–S bond, giving an ITO/SnS 2 /ZnIn 2 S 4 /UCNPs/CdSe heterojunction structure. When irradiated with 980 nm near-infrared (NIR) light, the UV–visible light emitted by the UCNPs could excite the nanocomposite , producing an enhanced photoelectric reaction. Subsequently, CEA aptamer and DNA2-modified SiO 2 were added to form a Y-shaped DNA structure. At this time, the photocurrent was significantly reduced by the combination of the light-blocking effect of SiO 2 and the departure of CdSe NPs from the electrode surface . When the target CEA was added, the recognition between CEA and the aptamer led to the collapse of the Y-shaped DNA structure, the restoration of hairpin DNA and the proximity of CdSe to the electrode. Accordingly, the photocurrent signals enhanced again. Under optimal experimental conditions, the detection limit as low as 0.3 pg mL −1 was obtained with good selectivity , achieving a sensitive “on-off-on” photoelectrochemical sensor for CEA detection.

BN/Cu/CNT nanoparticles as an efficient tri-functional electrocatalyst for ORR and OER

Jiemei Yu,Zhankun Jiang,Taizhong Huang,Chengchun Tang

Preparing economic, stable, and highly efficient non-precious-metal materials for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of great significance to the development of storage technologies and energy conversion. In this manuscript, we report a novel Cu based nano-catalyst as an electrode material fabricated by complexation-reduction method. Benefit from the stable of h-NB and the good electrical conductivity of CNT , the tri-functional electrocatalyst BN/Cu/CNT displays enhanced activity towards ORR and with the high current density of 0.95 mA/cm 2 , which is comparable to that of commercial Pt/C catalyst (cathodic peak current: 1.05 mA/cm 2 ). The BN/Cu/CNT also demonstrates high catalyst activity for the OER. From the rotating disk electrode and rotating ring-disk electrode tests, the number of electrons exchanged during the ORR is revealed to be 3.92, suggesting a 4e − pathway of O 2 reduction to H 2 O. The as prepared catalyst also has good stability and superior methanol tolerance to the commercial Pt/C catalyst in alkaline medium . Thus, it is anticipated that the BN/Cu/CNT catalyst is surely helpful for providing a new space to develop Pt-free catalyst.

Designed synthesis of multifunctional lignin-based adsorbent for efficient heavy metal ions removal and electromagnetic wave absorption

Boyu Du,Lanfang Chai,Qian Zheng,Ying Liu,Xing Wang,Xiaohong Chen,Shangru Zhai,Jinghui Zhou,Run-Cang Sun

Multifunctional lignin-based adsorbents, which have shown great application prospect, have attracted widespread attention. Herein, a series of multifunctional lignin-based magnetic recyclable adsorbents were prepared from carboxymethylated lignin (CL), which was rich in carboxyl group (-COOH). After optimizing the mass ratio of CL to Fe 3 O 4 , the prepared CL/Fe 3 O 4 (3:1) adsorbent showed efficient adsorption capacities for heavy metal ions. The kinetic and isotherm nonlinear fitting studies revealed that the adsorption process followed the second-order kinetic and Langmuir models, and the maximum adsorption capacities (Q max ) of CL/Fe 3 O 4 (3:1) magnetic recyclable adsorbent for Pb 2+ , Cu 2+ and Ni 2+ ions reached 189.85, 124.43 and 106.97 mg/g, respectively. Meanwhile, after 6 cycles, the adsorption capacities of CL/Fe 3 O 4 (3:1) for Pb 2+ , Cu 2+ and Ni 2+ ions could keep at 87.4 %, 83.4 % and 82.3 %, respectively. In addition, CL/Fe 3 O 4 (3:1) also exhibited excellent electromagnetic wave absorption (EMWA) performance with a reflection loss (RL) of −28.65 dB at 6.96 GHz under the thickness of 4.5 mm, and its effective absorption bandwidth (EAB) achieved 2.24 GHz (6.08–8.32 GHz). In short, the prepared multifunctional CL/Fe 3 O 4 (3:1) magnetic recyclable adsorbent with outstanding adsorption capacity for heavy metal ions and superior EMWA capability opens a new avenue for the diversified utilization of lignin and lignin-based adsorbent.

Mn2+-Activated Photostimulable Persistent Nanophosphors by Pr3+ Codoping for Rewritable Information Storage

Feng Gao,Qing Pang,Dangli Gao,Chaoyang Jia,Hong Xin,Yong Pan,Yuhua Wang,Sining Yun

Photostimulable luminescence (PSL) nanophosphors, which exhibit superior features including controllable energy storage and efficient photon release upon light stimulation, are desirable for optical signal storage. However, trap tuning of the storage phosphor remains a great challenge. Herein, the PSL of Zn2GeO4:Mn2+ nanophosphors is enhanced via creating deep traps through nonequivalent Pr3+ doping. The possible enhanced mechanisms are analyzed combined with doping models using the first-principles theory. A mechanism is proposed based on changing the coordination environment of Mn2+, creating deep traps and tuning the band gap structure, and thus providing the chance for electrons’ photoionization and PSL generation. As a result, the prepared nanophosphors demonstrate the superior functionalities for optical signal storage. This work not only offers an insight into defect engineering through doping strategies for developing PSL materials but also supplies a good candidate for optical information storage.

Porous highly fluorinated polyimide/polydopamine nanocomposite films with simultaneously enhanced toughness, UV-shielding and photostability for aerospace applications

Qing Li,Yujuan Guo,Chaoliu Ouyang,Shunmin Yi,Sheng Liu

Polydopamine (PDA), also known as artificial melanin, was adopted as ultraviolet absorbent to prepare a series of porous highly fluorinated polyimide/polydopamine (FPI/PDA) films by cyclodehydration via chemical and thermal imidization. The hydrogen bond and porous structure endowed the reinforced thermal, mechanical, UV-shielding and photostability. The initial decomposition and glass transition temperatures of FPI/PDA (1 wt %) film were as high as 461.5 °C and 341.5 °C, respectively beyond pure FPI by 54.1 °C and 26.0 °C. The stress-strain curves indicated that tensile strength and fracture elongation first increased and then decreased with the increase of PDA content, and reached the maximum at 0.5 wt % PDA content, which were 1.41 and 29.47 times of FPI, respectively. UV–vis transmittance spectra, curcumin photolysis and recyclability measurement confirmed the splendid UV-shielding properties with simultaneous excellent visible light transmittance and durability of porous FPI/PDA film. FTIR and AFM manifested its superior photostability with mild variation in carbonyl absorption peaks and surface roughness after 720 h UV irradiation. The above enhancement mechanisms included synergistic UV absorption of porous FPI and PDA, photothermal conversion in a stable FPI, and PDA's free radical trapping, promoting porous FPI/PDA film as an aerospace UV shielding material.

In vitro Antitumor Properties of Fucoidan-Coated, Doxorubicin-Loaded, Mesoporous Polydopamine Nanoparticles

Hongping Xu,Junhong Ling,Han Zhao,Xinyi Xu,Xiao-kun Ouyang,Xiaoyong Song

Chemotherapy is a common method for tumor treatment. However, the non-specific distribution of chemotherapeutic drugs causes the death of normal cells. Nanocarriers, particularly mesoporous carriers, can be modified to achieve targeted and controlled drug release. In this study, mesoporous polydopamine (MPDA) was used as a carrier for the antitumor drug doxorubicin (DOX). To enhance the release efficiency of DOX in the tumor microenvironment, which contains high concentrations of glutathione (GSH), we used N,N-bis(acryloyl)cysteamine as a cross-linking agent to encapsulate the surface of MPDA with fucoidan (FU), producing MPDA-DOX@FU-SS. MPDA-DOX@FU-SS was characterized via transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy (XPS), and its antitumor efficacy in vitro was investigated. The optimal conditions for the preparation of MPDA were identified as pH 12 and 20 °C, and the optimal MPDA-to-FU ratio was 2:1. The DOX release rate reached 47.77% in an in vitro solution containing 10 mM GSH at pH 5.2. When combined with photothermal therapy, MPDA-DOX@FU-SS significantly inhibited the growth of HCT-116 cells. In conclusion, MPDA-DOX@FU-SS may serve as a novel, highly effective tumor suppressor that can achieve targeted drug release in the tumor microenvironment.Keywords:mesoporous polydopamine;antitumor;nanomedicine;photothermal synergistic chemotherapy

A magnetically recyclable lignin-based bio-adsorbent for efficient removal of Congo red from aqueous solution

Enmin Zong,Runfang Fan,Hao Hua,Jiayao Yang,Shengtao Jiang,Jinfeng Dai,Xiaohuan Liu,Pingan Song

It has been always attractive to design a sustainable bio-derived adsorbent based on industrial waste lignin for removing organic dyes from water. However, existing adsorbent strategies often lead to the difficulties in adsorbent separation and recycling. Herein, we report a novel magnetically recyclable bio-adsorbent of Mg(OH) 2 /Fe 3 O 4 /PEI functionalized enzymatic lignin (EL) composite (EL-PEI@Fe 3 O 4 -Mg) for removing Congo red (CR) by Mannish reaction and hydrolysis-precipitation. The Mg(OH) 2 and PEI functionalized EL on the surface act as active sites for the removal of CR, while the Fe 3 O 4 allows for the easy separation under the help of a magnet. As-obtained EL-PEI@Fe 3 O 4 -Mg forms flower-like spheres and has a relatively lager surface area of 24.8 m 2  g −1 which is 6 times that of EL. The EL-PEI@Fe 3 O 4 -Mg exhibits a relatively high CR adsorption capacity of 74.7 mg g −1 which is 15 times that of EL when initial concentration is around 100 mg L −1 . And it can be easily separated from water by applying an external magnetic field. Moreover, EL-PEI@Fe 3 O 4 -Mg shows an excellent anti-interference capability according to the results of pH values and salt ions influences. Importantly, EL-PEI@Fe 3 O 4 -Mg possesses a good reusability and a removal efficiency of 92 % for CR remains after five consecutive cycles. It is illustrated that electrostatic attraction, π-π interaction and hydrogen binding are primary mechanisms for the removal of CR onto EL-PEI@Fe 3 O 4 -Mg. This work provides a novel sustainable strategy for the development of highly efficient, easy separable, recyclability bio-derived adsorbents for removing organic dyes, boosting the efficient utilization of industrial waste lignin.

A Novel Large-Diameter Optical Fiber Glucose Biosensor Based on Glucose Oxidase– Graphene Oxide–Gold Nanoparticles

Bing Xu,Xiaoying Xiang,Liyun Ding,Zhihui Luo,Jue Zhao,Jun Huang,Haijun Li,Xingdong Jiang

Photocatalytic activity and mechanism of cerium dioxide with different morphologies for tetracycline degradation

Mengjie Lu,Min Liu,Yaxin Wei,Huihui Xie,Wenbo Fan,Junzi Huang,Jindou Hu,Peng Wei,Weidong Zhang,Yahong Xie,Ying Qi

Cerium dioxide (CeO 2 ) semiconductor has received wide attention in the field of energy and environment due to its excellent oxygen storage capacity and abundant oxygen vacancies (OVs). Previous research demonstrated that the morphology and structure of the crystal had great influence on the physicochemical properties of the material. Herein, CeO 2 nanomaterials with different morphologies were prepared via a facile hydrothermal and template method. Systematic material characterizations suggested that the synthetic CeO 2 has different morphologies with CeO 2 nanorods (NRs), nanocubes (NCs), nanosheets (NSs), hollow spheres (HSs), and mesoporous CeO 2 (m-CeO 2 ), respectively. The visible-light-induced degradation performance of CeO 2 with different morphologies was investigated in aqueous solution using the antibiotic tetracycline (TC) as a model pollutant. The experimental results exhibited that the CeO 2 NRs possessed the best adsorption capacity and photocatalytic activity and more than 89.35% TC could be removed within 90 min. Combined with the XPS characterization results implied that the concentrations of Ce 3+ and OVs on the surface of CeO 2 with different morphologies were discrepancy, and the improved photocatalytic performance of CeO 2 NRs was mainly due to the higher concentration of Ce 3+ and OVs on the catalyst surface. These results confirmed that the regulation of the morphology of CeO 2 could effectively enhance its photocatalytic activity. Furthermore, the results of active species trapping experiments proved that the super oxide anion (•O 2 - ) radical and hole (h + ) played dominant roles in the degradation of TC.

Acidic and hypoxic tumor microenvironment regulation by CaO2-loaded polydopamine nanoparticles

Ruan Shuangrong,Yin Weimin,Chang Jiao,Yang Yan,Sun Jiuyuan,Ma Xiaoyi,Liu Ying,Zang Jie,Liu Yiqiong,Li Yongyong,Ren Tianbin,Dong Haiqing

Hypoxia and high accumulation of lactic acid in the tumor microenvironment provide fertile soil for tumor development, maintenance and metastasis. Herein, we developed a calcium peroxide (CaO2)-loaded nanostructure that can play a role of “one stone kill two birds”, i.e., acidic and hypoxic tumor microenvironment can be simultaneously regulated by CaO2 loaded nanostructure. Specifically, CaO2-loaded mesoporous polydopamine nanoparticles modified with sodium hyaluronate (denoted as CaO2@mPDA-SH) can gradually accumulate in a tumor site. CaO2 exposed in acidic microenvironment can succeed in consuming the lactic acid with oxygen generation simultaneously, which could remodel the acid and hypoxia tumor microenvironment. More importantly, the relief of hypoxia could further reduce lactate production from the source by down-regulating the hypoxia inducible factor-1α (HIF-1α), which further down-regulated the glycolysis associated enzymes including glycolysis-related glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). As a result, CaO2@mPDA-SH alone without the employment of other therapeutics can dually regulate the tumor hypoxia and lactic acid metabolism, which efficiently represses tumor progression in promoting immune activation, antitumor metastasis, and anti-angiogenesis.

Camptothecin-Loaded and Manganese Dioxide-Coated Polydopamine Nanomedicine Used for Magnetic Resonance Imaging Diagnosis and Chemo-Photothermal Therapy for Lung Cancer

Mingliang Su,Yukun Chen,Lijun Jia,Zhanxia Zhang

Introduction Camptothecin (CPT) is a cytotoxic quinolone alkaloid (isolated from a traditional Chinese medicine Camptotheca acuminata), used for the treatment of various malignancies, which inhibits DNA topoisomerase I (Topo I). However, its drawbacks, such as poor water solubility, stability, and highly toxic side effects, limit its clinical application. Therefore, CPT needs to be prepared as a nanomedicine to improve solubility, reduce side effects, and synergize with other therapies to improve efficacy. Methods In this work, we constructed CPT NPs (nanoparticles), which were CPT-loaded and manganese dioxide (MnO 2 )-coated polydopamine (PDA) nanomedicine. In vitro, we explored the antitumor effect including CPT NPs-induced cell proliferation inhibition, apoptosis and ferroptosis for tumor cell lines. In vivo, we established LLC tumor-bearing mice model to evaluate their tumor imaging and anticancer effects. Results CPT NPs improve the water solubility and stability of CPT and reduce its toxic effects. It has good biocompatibility, excellent photothermal conversion ability for photothermal therapy (PTT) and pH release in the tumor microenvironment. It can inhibit tumor cell proliferation, induce apoptosis and result in ferroptosis of tumor cells. More significantly, this nanomedicine can provide information for the location and diagnosis of tumors via magnetic resonance imaging. In general, the nanomedicine integrated with diagnosis and treatment has excellent anticancer effect. Discussion Altogether, this nanomedicine possesses the ability to diagnose and therapy through magnetic resonance imaging and chemo-photothermal therapy, respectively. In addition, the integrated diagnosis and treatment nanomedicine has potential clinical application prospects through treating lung cancer with high efficiency and low side effect. It can support the construction of related nano-delivery systems.