SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Fuming Sang,Menglin Li,Suyao Yin,Huahua Shi,Yan Zhao,Zhizhou Zhang
Glutathione (GSH) plays a critical role in biological defense system and is associated with numerous human pathologies. However, it still remains a challenge for fluorescent detection of GSH over cysteine (Cys) and homocysteine (Hcy) because of their similar structures. In this work, MnO 2 nanosheets can efficiently quench the fluorescence of gold nanoclusters (Met-AuNCs) prepared by blending methionine and HAuCl 4 owing to their superior absorption capability. However, GSH can reduce MnO 2 nanosheets into Mn 2+ which leads to the fluorescence recovery of Met-AuNCs. More intriguingly, GSH can dramatically and selectively enhance the fluorescence intensity of Met-AuNCs. Hence, a low background, ultrasensitive fluorescent detection of GSH was obtained with a detection limit of 68 nM. Moreover, the assay has been successfully used for GSH detection in human serum samples and cellular imaging with high selectivity over Cys and Hcy.
研究领域:
生物化学
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分析化学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jiankang Wang,Taiping Xie,Guokang Han,Quanxi Zhu,Yajing Wang,Yuan Peng,Songli Liu,Zhongping Yao
Cost-effective and low-toxicity of MnO 2 is regarded as a promising alternative to Co-based catalyst for peroxymonosulfate (PMS) activation to degrade recalcitrant organic pollutants. However, the sluggish Mn(IV)/Mn(III) redox cycling and limited specific surface area greatly hampered its wide application. To solve this challenge, a mesoporous γ-Fe 2 O 3 @MnO 2 magnetic catalyst with SiO 2 assistance (s-γ-Fe 2 O 3 @MnO 2 ) was synthesized. Physicochemical characterization confirmed part MnO 2 was coated on γ-Fe 2 O 3 surface while the other existed independently. Furthermore, BET surface area of s-γ-Fe 2 O 3 @MnO 2 was more than two times that of the counterpart without SiO 2 assistance (ws-γ-Fe 2 O 3 @MnO 2 ). s-γ-Fe 2 O 3 @MnO 2 exhibited enhanced PMS activation capacity with 97.6% phenol removal efficiency within 80 min, superior to other samples. Various influencing parameters on phenol oxidation were optimized. Reactive oxygen species (ROS) scavenging experiment and electron paramagnetic resonance (EPR) validated co-existence of hydroxyl radicals (·OH) and sulfate radicals (SO 4 · − ) as well as singlet oxygen ( 1 O 2 ) during PMS activation. However, phenol degradation was a non-radical oxidation process dominated by 1 O 2 . A rational reaction mechanism was proposed. Fe(II) promoted Mn(IV)/Mn(III) redox cycling and the enlarged surface area derived from SiO 2 mediated templating synthesis were responsible for the enhanced phenol degradation. This strategy can give a guidance for synthesis of highly efficient catalyst for sewage remediation.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2025
·
IF 5.1
Huangying Guo,Wenyu Wan,Pengcheng Deng,Yang Luo,Xing Zhou
Cross and secondary electromagnetic pollution is a major challenge in current electromagnetic interference (EMI) mitigation. In this study, Fe3O4@MnO2 composite microspheres and AgNWs were prepared using modified solvothermal and hydrothermal methods. By optimizing the fabrication process and structural design of electromagnetic shielding composite films, we successfully constructed a composite film with superior shielding performance and reduced thickness. The Fe3O4@MnO2 composite exhibited an SEA/SET ratio of 83.32%, along with a high absorption coefficient A, indicating its dominant role in electromagnetic wave absorption, thereby mitigating excessive reflection. Results demonstrated that the gradient network-structured film possessed significantly enhanced electromagnetic wave absorption and attenuation capabilities compared to other three composite materials. The SEA/SET of the gradient network-structured film reached 86%, with a maximum SET of 58.65 dB. This hierarchical structure not only improves shielding effectiveness at reduced thickness but also enhances absorption, achieving the ultimate goal of high absorption with low reflection while minimizing resource consumption.
研究领域:
材料科学
·
电磁学
·
纳米技术
·
复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Ping Li,Shujuan Zhan,Lan Yao,Ya Xiong,Shuanghong Tian
Herein we reported the first example of preparing α-MnO 2 by selective acid etching from Mn-containing spinel. The defects, facet, and surface area of α-MnO 2 were cooperatively engineered by an all-in-one acid etching method to enhance the defect accessibility to the reactants. The obtained highly porous α-MnO 2 nanorods have rich defects of Mn 3+ (24.9%) and oxygen vacancies (31.4%), mainly active crystal facets of (110), and an ultrahigh surface area of 271.1 m 2 /g. With α-MnO 2 nanorods as the catalysts, more than 90.9% of 4-chlorophenol can be degraded within 12 min by catalytic ozonation in a wide work pH of 4.5–10.5. The experiments and DFT theory calculations reveal that α-MnO 2 with (110) facet promotes the adsorption and activation of ozone directly over the defects or indirectly over H 2 O adsorbed on the defects. Thus, more reactive oxygen species (e.g., •OH, •O 2 - , 1 O 2 , surface *O) are generated and get involved in pollutant degradation. This work provides a facile method to maximize the defect accessibility, and a deeper mechanistic study to understand the roles of the defects.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 413
·期 17
·4451-4458
·
IF 4.157
Liu Meng-Xian,Zhang He,Chen Shuai,Yu Yong-Liang,Wang Jian-Hua
Robust and sensitive cell-based enzyme-linked immunosorbent assay (CELISA) is of great significance in the diagnosis and screening of cancer. However, the method is limited by the high rate of negative results attributed to the instability of horseradish peroxidase (HRP), H 2 O 2 , and antibody. Here, we construct a folic acid–functionalized in situ-grown MnO 2 nanosheet/graphene oxide hybrid (FA-MnO 2 /GO) with oxidase-like activity instead of the anti-folate receptor antibody in traditional CELISA to resist the possible negative interference arising from unstable HRP, H 2 O 2 , and antibodies for more robust colorimetric detection of cancer cells. The functionalization of FA enables the selective binding between hybrid and cancer cells through the over-expressed folate receptor, and then the binding events are converted into quantitative colorimetric signals though the oxidation of the chromogenic substrate TMB catalyzed by MnO 2 , allowing the detection of cancer cells with colorimetric method. Moreover, the construction of MnO 2 /GO hybrid can synergistically enhance the oxidase-like activity of MnO 2 and promote its dispersion in water, further ensuring the accuracy and sensitivity of the detection. A detection limit of 20 cancer cells is obtained by a plate reader, which is lower than those obtained by most reported CELISA methods for cancer cell detection, and as few as 75 cancer cells can be identified by the naked eye. This study not only provides a multifunctional sensing platform for robust and sensitive cancer cell detection, but also offers a promising oxidase-like mimic in the field of bioanalysis. Graphical abstract
研究领域:
生物化学
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医学诊断
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纳米材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Xiang Ran,Fang Pu,Zhenzhen Wang,Jinsong Ren,Xiaogang Qu
Accurate and facile differentiation of cell types is essential for accurate diagnosis and therapy of diseases. However, it remains challenging due to low specificity, requirement of sophisticated instruments, and tedious operation steps. Herein, a simple, washing- and label-free chemical tongue was constructed for differentiation of cell types. In the array-based sensing platform, DNA-ligand ensembles adsorbed on the surface of MnO 2 nanosheets were used as sensing probes. Instead of aptamers from cell-SELEX, the randomly designed DNA strands were used, offering versatile interactions with cells. The property that MnO 2 nanosheets can be degraded by intracellular glutathione makes the platform avoid the washing step. Eight types of cell lines were distinguished from each other after the data were treated with principal component analysis (PCA). In addition, a 95% of identification accuracy for the randomly selected unknown samples was achieved. The strategy shows an excellent performance not only in distinguishing cell lines but also in the identification of unknown cell samples.
研究领域:
生物化学
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纳米医学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Wanwei Jiang,Xijun Xu,Yuxuan Liu,Liang Tan,Fengchen Zhou,Zhiwei Xu,Renzong Hu
Aqueous zinc-ion batteries have emerged as prospective energy storage devices to partly replace organic ion batteries due to their high safety and eco-friendliness. Providing multifold synthesis methods of cathode materials is essential for Zn-ion battery development. Here, we demonstrated a practical strategy for the large-scale fabrication of high performance β-MnO 2 @C hybrid cathode materials by plasma assisted milling (P-milling). After P-milling for 10 h, the porous hybrid microparticles consisted of MnO 2 nanocrystallites , which combined and wrapped with the thin carbon layer derived from expanded graphite. The pores among the β-MnO 2 @C particles facilitated electrolyte infiltration during continuous cycling, while combining with carbon greatly enhanced the conductivity of the hybrids and helped to alleviate MnO 2 dissolution. Therefore, the β-MnO 2 @C hybrids delivered excellent cycle stability, with a high capacity of 130 mAh g −1 for 400 cycles at a current rate of 300 mA g −1 in an aqueous Zn(CF 3 SO 3 ) 2 electrolyte. This capacity retention was amongst the highest reported so far for MnO 2 -based cathode materials for Zn-ion batteries.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2018
·
IF 0
Lei Zhao,Xiaoqian Ge,Huijun Zhao,Liyi Shi,John A. Capobianco,Dayong Jin,Lining Sun
A double-sensitive drug release system based on MnO2 nanosheets was synthesized using a facile method for imaging guided chemotherapy in cancer cells. The upconversion nanoparticles (UCNPs) as core are used for upconversion luminescence (UCL) imaging, and the coating of mesoporous silica shows excellent ability for loading drug. The assembly with MnO2 nanosheets can respond to low intracellular pH and GSH in cancer cells. The obtained UCNPs@mSiO2–MnO2 nanoparticles with excellent biocompatibility can be applied as drug carriers. As expected, the UCNPs@mSiO2(DOX)–MnO2 (UCDMs) nanoconstruct loading with DOX offer practical chemotherapeutic effects in vitro, suggesting the active drug release in cancer cells. The luminescence intensity and magnetic resonance signals increased with the decomposition of the MnO2 nanosheets and the release of DOX under low pH and high levels of GSH. In addition, the UCDMs exhibit excellent intracellular UCL imaging, indicating that they can be used as a selective imaging agent in a cancerous environment. Thus, the UCDMs present potential application for use as theranostic agents in imaging guided therapy.
研究领域:
生物医学工程
·
肿瘤学
·
材料科学
✓ 已验证
产品关联
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Wei Guo,Linlin Hou,Biao Hou,Yalin Guo
Pseudocapacitive materials, e.g. , MnO 2 and Co 3 O 4 , can significantly enhance the energy density of supercapacitors because of Faradaic reactions that can take place with these materials. Single-component electrodes have shown insufficient performance due to limited variations in electrode structures. Herein, we report a hierarchical electrode through growing networked Co 3 O 4 @MnO 2 hierarchical nanosheets (HNS) arrays directly on Ni foam. We adopt a one-step hydrothermal reaction followed by a simple staged post-annealing treatment which simplifies the synthesis procedure. When used as electrodes for supercapacitors, the Co 3 O 4 @MnO 2 HNS electrode shows good electrochemical performance, such as high areal/specific capacitances of 2.85 F cm −2 /2374 F g −1 at a current density of 1 mA cm −2 and long-term cycling stability of 4500 cycles. These encouraging results demonstrate this electrode design strategy is promising for developing high capacitance electrode materials for high energy density supercapacitors.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2020
·Vol. 8
·期 43
·9943-9950
·
IF 5.344
Chunlei Yang,Yazhou Liu,Sa Su,Na Gao,Jing Jing,Xiaoling Zhang
The current trend of cancer therapy has changed from monotherapy to synergistic or combination therapies. Among the treatment strategies, photodynamic therapy (PDT) and starvation therapy are widely employed together. However, the therapeutic effect of these treatments could lead to strong resistance and poor prognosis due to tumor hypoxia. Therefore, a smart nanoplatform (MONs-GOx@MnO2-Ce6) has been constructed herein by the assembly of glucose oxidase (GOx)-coated mesoporous organosilica nanoparticles (MONs) and MnO2 nanosheets-chlorin e6 (Ce6), which form a nanosystem. Once MONs-GOx@MnO2-Ce6 enter tumor cells, it catalyzes the oxidation of glucose using oxygen (O2) and generates hydrogen peroxide (H2O2) and gluconic acid, the former of which may accelerate the decomposition of MnO2 nanosheets. The released MnO2 nanosheets would regenerate O2 in the presence of H2O2. In this case, MnO2 nanosheets serve as (i) a nanocarrier and fluorescence quencher for the photosensitizer Ce6, (ii) a degradable material that is activated by the tumor microenvironment (TME) for fluorescence recovery, and (iii) an O2-producing carrier that reacts with H2O2 for relieving hypoxia in the tumor, which contributes to the combined starvation/photodynamic cancer therapy since these treatment strategies need O2. MONs-GOx@MnO2-Ce6 could not only realize cancer cell imaging, but also reduce intracellular glucose uptake and Glut1 expression, inhibiting the metabolism of cancer cells. This strategy shows great potential for clinical applications.
研究领域:
肿瘤学
·
纳米医学
·
生物材料学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 38
·14814-14826
·
IF 8.262
Xiao Ge,Xiangyang Song,Yue Ma,Hongjian Zhou,Guozhong Wang,Haimin Zhang,Yunxia Zhang,Huijun Zhao,Po Keung Wong
The eutrophication of water bodies caused by the excessive release of phosphorus is becoming a serious world-wide environmental problem. To address this issue, the exploitation of three-dimensional (3D) hierarchical architectures will be an effective strategy for sequestrating phosphate and preventing the occurrence of eutrophication. In this study, 3D flower-like hierarchical iron containing MnO2 hollow microspheres have been successfully fabricated via a facile one-step template-free route for the efficient removal of phosphate. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) studies show that the microspheres obtained consist of numerous intertwining nanosheets. Strikingly, the thickness of these nanosheets can be elaborately modulated ranging from 30 to 2 nm via varying Fe/Mn ratios, accordingly resulting in variation in the resultant phosphate adsorption performance. The uptake of phosphate onto these hierarchical microspheres shows that the obtained hierarchical iron containing MnO2 hollow microspheres possess markedly enhanced phosphate removal performance over undoped counterparts regardless of the removal rate or efficiency; meanwhile, the enhanced effect becomes more obvious with increasing iron amount due to the larger specific surface area and abundant active sites. In particular, the hierarchical MnO2 microspheres with 15 at% Fe incorporation are capable of removing completely low concentration phosphate (below 10 ppm) at a dosage of 0.5 g L−1. In addition, the as-obtained materials exhibit high sorption selectivity toward phosphate over other coexisting ions or dissolved organic matter (DOC) at high levels, which can be ascribed to the unique hierarchical structures and strong interaction between Mn/Fe sites and phosphate, as confirmed by Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. Furthermore, the regenerated materials can be repeatedly used for five cycles without obvious degradation of performance, suggesting the sustainability of the adsorbents. By virtue of the high removal efficiency, fast adsorption kinetics, preferable sorption selectivity, as well as satisfactory recyclability, the obtained hierarchical iron containing MnO2 hollow microspheres will be promising in eliminating the phosphate pollution from eutrophic waters.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Qilei Yang,Qi Li,Lei Li,Yue Peng,Dong Wang,Yongliang Ma,Junhua Li
The elimination of benzene, a typical volatile organic pollutant, is one of the most challenging topics for environmental scientists. Catalytic oxidation technology is considered the most efficient approach for its elimination. Herein, we report the successful preparation of a novel α–MnO 2 –like rod catalyst via an acid etching route and propose YMn 2 O 5 mullite as a novel precursor. The optimized α–MnO 2 –like rod catalyst showed significantly improved benzene oxidation activity compared to the raw YMn 2 O 5 and commercial MnO 2 catalysts, resulting in 100 % benzene conversion at 200 °C at a GHSV of 60,000 mL g –1 h –1 . Notably, the α–MnO 2 –like rod catalyst performance at lower temperatures (100–175 ℃) exceeded that of a commercial Pt/Al 2 O 3 catalyst. The excellent catalytic performance of the α–MnO 2 –like rod catalyst is associated with its low–temperature reducibility and abundant surface–active oxygen species. During the acid etching process, more Mn 3+ is oxidized to Mn 4+ , and more surface oxygen vacancies are generated on the α–MnO 2 –like rod catalyst, which provides more adsorption sites for oxygen molecules to promote the benzene oxidation reaction. The α–MnO 2 –like rod catalyst should be a great alternative to commercial noble metal catalysts for the elimination of volatile organic pollutants, especially at lower temperatures.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）