ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Fuyan Wang,Yiliang Li,Yameng Han,Zhongju Ye,Lin Wei,Hai-Bin Luo,Lehui Xiao
In a clinical assay, enzymes are essential biomarkers for human disease diagnosis. In this work, a spectral-resolved single-particle detection (SPD) method is introduced to quantify alkaline phosphatase (ALP) activity in human serum with a supraparticle (SP) based on MnO2-modified gold nanoparticle (denoted as GNP@MnO2 SP) as the probe. In the presence of ALP, 2-phospho-l-ascorbic acid trisodium salt can be hydrolyzed into l-ascorbic acid, which serves as a good reduction agent to trigger the decomposition of the MnO2 shell on the GNP surface. Given that a trace amount of ALP exists, noticeable scattering color change can be detected at the single-particle level due to the sensitive localized surface plasmon resonance (LSPR) effect from GNPs. With spectral-resolved dark-field optical microscopy, a linear dynamic range of 0.06 to 2.48 mU/mL (R2 = 0.99) and a very low limit of detection of 5.8 μU/mL for the ALP assay are readily achieved, which is more sensitive over the methods based on ensemble sample measurement. As a consequence, this strategy opens a new avenue for the design of an ultrasensitive detection method for disease-correlated biomarker diagnosis in the future.
研究领域:
生物化学
·
医学诊断
·
光学显微技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zihan Xing,Linwei Li,Tao Liao,Jinyu Wang,Yuhao Guo,Ziqiang Xu,Wenqian Yu,Ying Kuang,Cao Li
Starvation therapy has shown promise as a cancer treatment, but its efficacy is often limited when used alone. In this work, a multifunctional nanoscale cascade enzyme system, named CaCO 3 @MnO 2 -NH 2 @GOx@PVP (CMGP), was fabricated for enhanced starvation/chemodynamic combination cancer therapy. CMGP is composed of CaCO 3 nanoparticles wrapped in a MnO 2 shell, with glucose oxidase (GOx) adsorbed and modified with polyvinylpyrrolidone (PVP). MnO 2 decomposes H 2 O 2 in cancer cells into O 2 , which enhances the efficiency of GOx-mediated starvation therapy. CaCO 3 can be decomposed in the acidic cancer cell environment, causing Ca 2+ overload in cancer cells and inhibiting mitochondrial metabolism. This synergizes with GOx to achieve more efficient starvation therapy. Additionally, the H 2 O 2 and gluconic acid produced during glucose consumption by GOx are utilized by MnO 2 with catalase-like activity to enhance O 2 production and Mn 2+ release. This process accelerates glucose consumption, reactive oxygen species (ROS) generation, and CaCO 3 decomposition, promoting the Ca 2+ release. CMGP can alleviate tumor hypoxia by cycling the enzymatic cascade reaction, which increases enzyme activity and combines with Ca 2+ overload to achieve enhanced combined starvation/chemodynamic therapy. In vitro and in vivo studies demonstrate that CMGP has effective anticancer abilities and good biosafety. It represents a new strategy with great potential for combined cancer therapy.
研究领域:
肿瘤学
·
生物医学工程
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Hengjia Zhu,Peng Liu,Lizhang Xu,Mengzhu Wang,Jianming Pan,Xiangheng Niu
Due to their great threat to human health and the environment, it is always of significance to develop efficient tools to monitor pesticide residues. Although the enzyme inhibition-based strategy is considered as a potential method and has been intensively explored for pesticide analysis, both vulnerable enzymatic activity and tedious operation greatly hinder its practical applications. Developing robust, easy-to-use and efficient devices for pesticide sensing is still challenging. Herein, we recommend an enzyme-nanozyme integrated hierarchically porous hydrogel (AChE-MnO 2 @HPH) for the convenient detection of pesticides. MnO 2 microspheres were first employed as an emulsion stabilizer to fabricate MnO 2 @HPH by thermal polymerization, and AChE was then immobilized into the MnO 2 @HPH via a fast self-absorption process. With the unique porous structure and hydrophilic microenvironment, the constructed AChE-MnO 2 @HPH exhibited excellent enzymatic activity and stability as well as rapid response toward pesticides through inhibiting the activity of AChE. By applying a smartphone to read the color information originating from the chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) catalyzed by oxidase-mimicking MnO 2 , highly sensitive and convenient determination of fenthion, an organophosphorus pesticide model, was achieved with a detection limit down to 0.63 ng mL −1 . Excellent performance robustness over 30 storage days and reliable detection of the target in real food samples were also demonstrated. With the advantages of easy operability, free of equipment, and good detection performance and long-term stability, the integrated AChE-MnO 2 @HPH will find promising use for pesticide residue in-field analysis.
研究领域:
生物化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Chenglong Li,Shuang Wang,Yinghe Cui,Xiaodong Wang,Zhipeng Yong,Dan Liang,Yue Chi,Zhe Wang
Two-dimensional transition metal carbides/nitrides (MXene) have excellent physicochemical properties, but the restacking of MXene films restricts their development towards flexible supercapacitors with high energy density . Introducing Polyaniline (PANI) into the MXene layer and expanding the interlayer distance of the MXene can reduce the effect of restacking on the MXene after compounding. However, despite the excellent electronic conductivity of the composited MXene/PANI (MP), its internal slow ionic kinetics becomes a fundamental limitation of the electrochemical performance after the MP loading increases. To compensate for this weakness, MP films are often scaled down to a few micrometers in size (<2 mg cm −2 ), which limits their development. Here, we introduce α-Fe 2 O 3 /MnO 2 (FM) into MP for the first time by designing a sandwich structure, which significantly improves the bulk capacitance. Due to a large number of active sites and good hydrophilic properties on the MXene surface, FM can interact with the MP. By complexing with MP, the accumulation and loss of FM can be reduced. At the same time, the effect of increasing loading on the electrochemical performance of MP can be compensated. The MXene-PANI/α-Fe 2 O 3 -MnO 2 /MXene-PANI (MP/FM/MP) electrode still exhibits high capacitive performance (661 F g −1 , 3138 mF cm −3 ) when the MP loading reaches 5 mg cm −2 , with excellent mechanical properties and increased flexibility. In addition, the corresponding symmetric supercapacitor also shows a remarkable energy density of 53.32 Wh·L −1 (17.45 Wh kg −1 ). This study provides a way to fabricate MXene-based electrodes with high loadings by designing sandwich-structured electrodes.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 17
·2200271
·
IF 6.389
Ke Wang,Enhui Ma,Hong Wang
Self-propelled magnetic MnO 2 @pollen micromotors have been developed as active heterogeneous catalysts of peroxymonosulfate (PMS) activation for efficient degradation of antibiotics. The MnO 2 nanosheets (NSs) and Fe 3 O 4 nanoparticles (NPs) are constructed on hollow pollens with small openings, endowing the natural materials with multifunctional properties. MnO 2 NSs can decompose H 2 O 2 to provide propulsion for micromotor movement, and also cooperate with Fe 3 O 4 NPs to activate PMS to produce active free radicals SO 4 ·− . Together with the OH· generated by Fe 3 O 4 NPs and H 2 O 2 , the prepared micromotor catalyst can realize the degradation of tetracycline (TC) within several minutes. The self-propulsion and abundant bubble formation cause effective fluid mixing and intensification of mass transfer, making up the low diffusivity defect of traditional heterogeneous catalysts. Moreover, the magnetic properties lay a foundation for the long-range magnetic control and reutilization of heterogeneous catalysts, avoiding wastage and secondary contamination. The proposed self-propelled pollen micromotors provide a highly efficient, economic, and environmentally friendly platform for the degradation of antibiotics.
研究领域:
环境科学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Wenhui Dang,Chengjun Dong,Zhifang Zhang,Gang Chen,Yude Wang,Hongtao Guan
MnO 2 was self-grown on carbon fiber paper (CFP) via a facile redox reaction , which is constructed by interconnected ultrathin nanosheets array. The CFP acts as both a supporting scaffold and a reducing agent for MnO 2 growth. The obtained MnO 2 /CFP composite was directly used as electrodes for supercapacitors , delivering a high specific capacitance of 713.7 F/g (0.5 A/g). Cyclic stability testing of the MnO 2 /CFP electrode reveals 86.8% retention in specific capacitance after 1200 cycles at 5.0 A/g. The nanosheet morphology of the MnO 2 on CFP brings about more efficient electroactive sites and facilitates the electrolyte penetration, allowing greater access for ions to active reaction sites. Hence, the attractive electrochemical performances exhibited by this MnO 2 /CFP electrode endow them potentially promising candidates for supercapacitors.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2023
·Vol. 97
·期 13
·2950-2957
·
IF 0.7
Wang Jinbo,Yu Linli,Qin Ruixiang,Chen Lirong,Wang Rongtong,Zhao Shuai,Qiu Yifang,Xia Bin,Wang Yu,Li Jing
Abstract A highly active MnO 2 catalyst with mixed crystal forms for the catalytic combustion of ethyl acetate was successfully prepared. The characterization results showed that increasing the hydrothermal temperature promotes the transformation of MnO 2 from α phase to β phase, and the microscopic morphology gradually evolves from stacked granular to rod-like structure, thereby obtaining biphasic mesoporous MnO 2 . In particular, the lattice fringes of α and β phases observed in HRTEM further proved that MnO 2 possesses a dual-phase structure. XPS verified that MnO 2 –180°C has the highest O ads /O latt (0.45) and Mn 3+ /Mn 4+ (0.90) ratio, and as oxygen vacancies appear together with the formation of Mn 3+ ions. The MnO 2 –180°C catalyst displayed the best performance that T 99 (the temperature needed for 99% conversion) is as low as 170°C even though under the high space velocity of 68 000 mL g –1 h –1 . Furthermore, the catalytic activity remained unchanged after 24 h of continuous reaction, demonstrating excellent low-temperature catalytic performance and good stability.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Siyang Sun,Yuhan Wang,Lin Zhou,Xiaoyu Wang,Chunli Kang
In this study, we constructed MnO 2 /organic acid (OA) systems using MnO 2 colloid, the most reactive phase of Mn(IV), and two kinds of OA (oxalic acid and l -tartaric acid). We investigated the effect of OA on tetracycline (TC) degradation by MnO 2 . The results show that both OA obviously accelerate TC degradation by MnO 2 . Mn(III) formed during the reaction lead to the acceleration. Mn(III)-oxalate complex formed in oxalic acid system resulted in the lower degradation efficiency than that in l -tartaric acid system. The acceleration of oxalic acid was decreased when the concentration was more than 75 μM, and even completely disappeared with the concentration of 500 μM, owning to the fact that excess oxalic acid decreased the pH and some MnO 2 was fast reduced to Mn 2+ by oxalic acid and unable to react with TC. The impact of pH on TC degradation resulted from the influences of H + on MnO 2 redox potentials and TC deprotonation. And acidic conditions accelerated TC degradation. The addition of Mg 2+ , Ca 2+ , Fe 3+ and Zn 2+ exhibited an inhibitory effect in both systems for their occupying reactive sites on MnO 2 surface and blocking the access of TC to MnO 2 . Similar intermediates in the two systems were detected, indicating a similar TC degradation mechanism including a series of reactions like dehydration, hydroxylation and oxidation. The MnO 2 /OA system provides an efficient treatment of TC in wastewater. And it is also noticeable that MnO 2 /OA system should also have an important effect on the fate of pollutants in environment, from our results.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
ChemNanoMat
·
2026
·Vol. 12
·期 2
·e70200
·
IF 2.6
Zirui Huang,Chifei He,Yuekuan Sun,Wenjuan Liu
Micro/nanomotors (MNMs) hold significant promise for environmental remediation, yet their practical deployment remains constrained by limited propulsion efficiency, high fabrication costs, and complex manufacturing processes. Herein, we report a facile redox reaction coupled with an in situ deposition strategy for the scalable fabrication of three-dimensional flower-like MnO 2 /NiM layered double hydroxide (LDH) micromotors (M = Al, Fe, or Co) for efficient tetracycline removal. Powered by hydrogen peroxide, MnO 2 catalytically decomposes H 2 O 2 to generate oxygen bubbles, which serve as the driving force for autonomous motion. Under the conditions of 3% H 2 O 2 and 0.5% SDS, the MnO 2 /NiM-LDH micromotors exhibit good propulsion performance, achieving maximum speeds of 349.9, 244.2, and 27.3 μm/s for M = Al, Fe, and Co, respectively. During the catalytic process, reactive free radicals are generated, enabling effective tetracycline degradation. Notably, the addition of surfactants induces the accumulation of oxygen bubbles on the solution surface. This phenomenon promotes the contact between micromotors and tetracycline, thereby facilitating degradation and separation. In the test system, the MnO 2 /NiCo-LDH micromotors exhibit outstanding performance, with up to 93.3% removal of tetracycline (100 mg/L) in neutral water. This work highlights their significant potential in the environmental remediation of organic pollutants.
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 13
·7309-7317
·
IF 7.76
Ziya Wang,Fengping Wang,Yan Li,Jianlin Hu,Yanzhen Lu,Mei Xu
Structure designing and morphology control can lead to high performance pseudocapacitive materials for supercapacitors. In this work, we have designed interlinked multiphase Fe-doped MnO2 nanostructures (α-MnO2/R-MnO2/ε-MnO2) to enhance the electrochemical properties by a facile method. These hierarchical hollow microspheres assembled by interconnected nanoflakes, and with plenty of porous nanorods radiating from the spherical shells were hydrothermally obtained. The supercapacitor electrode prepared from the unique construction exhibits outstanding specific capacitance of 267.0 F g−1 even under a high mass loading (∼5 mg cm−2). Obviously improved performances compared to pure MnO2 are also demonstrated with a good rate capability, high energy density (1.30 mW h cm−3) and excellent cycling stability of 100% capacitance retention after 2000 cycles at 2 A g−1. The synergistic effects of alternative crystal structures, appropriate crystallinity and optimal morphology are identified to be responsible for the observations. This rational multiphase composite strategy provides a promising idea for materials scientists to design and prepare scalable electrode materials for energy storage devices.
研究领域:
材料科学
·
储能
·
纳米材料
·
电化学
·
超级电容器
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 8
·4058-4066
·
IF 8.867
Jian Zhang,Jie Han,Minggui Wang,Rong Guo
Multifunctional magnetic adsorbents containing MnO2 and polyaniline (PANI) with optimized adsorption properties toward heavy metal ions have been developed. In particular, Fe3O4 spheres were chosen as the magnetic core, followed by PANI and MnO2 coating, realizing the formation of Fe3O4/PANI/MnO2 core–shell hybrids. The as-synthesized Fe3O4/PANI/MnO2 core–shell hybrids showed a hierarchical structure with a large surface area and high magnetic saturation value. In comparison with Fe3O4/PANI and Fe3O4/MnO2 core–shell hybrids, Fe3O4/PANI/MnO2 core–shell hybrids displayed the highest adsorption capacity toward heavy metal ions (including Cd(II), Zn(II), Pb(II) and Cu(II)), thanks to the integrated physical and chemical adsorption behaviors resulting from MnO2 inorganic oxide and the PANI polymer. The developed multifunctional Fe3O4/PANI/MnO2 adsorbents synthesized by a facile and economic route are believed to show high potential in environmental remediation for heavy metal removal.
研究领域:
环境科学
·
材料化学
·
纳米技术
·
水处理
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Cong Chen,Minjie Shi,Yue Zhao,Cheng Yang,Liping Zhao,Chao Yan
Although manganese dioxide (MnO 2 ) is of great promise as the cathode material for aqueous Zn-ion batteries (ZIBs), its capacity decreases sharply during cycles due to the irreversible phase transition and Mn dissolution, consequently hindering the large-scale practical application. Herein, for the first time, a novel Al-intercalation engineering of MnO 2 cathode has been proposed for aqueous ZIBs, in which the structural regulation and Zn 2+ storage performance of Al-intercalated MnO 2 (denoted as AMO) cathode are deeply investigated. Electrochemical testing results indicate significant improvement in specific capacity (401.7 mAh g −1 ) and cycling retention (~94.5% over 2000 cycles) of the AMO cathode, which is owing to the effective Al-intercalation that result in the formation of strong Al-O bonds in tunnel-type MnO 2 framework. This reasonable configuration not only optimizes charge/ion state and electronic bandgap, but also ensures reversible phase transition and alleviates the Mn dissolution of AMO cathode, which are further demonstrated by the density functional theory (DFT) calculations and in-situ Raman investigation upon charging-discharging. As a proof of concept, coin-type and flexible aqueous ZIBs based on such AMO cathode are effectively fabricated, and they both achieve excellent electrochemical behaviors, revealing the great potential applications in energy technologies and portable/wearable electronics.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）