MICROCHIMICA ACTA
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2019
·Vol. 186
·期 5
·1-7
·
IF 5.479
Tan Qingqing,Kong Weisu,Sun Han,Qin Xia,Qu Fengli
A fluorometric turn-on assay is described for ascorbic acid (AA). It is based on the controlled release of polyallylamine-stabilized gold nanoclusters (polyallylamine-AuNCs) from MnO 2 nanosheets. In an aqueous solution of near-neutral pH value, the positively charged capped AuNCs are adsorbed on the surface of the negatively charged MnO 2 nanosheets. The adsorption leads to the quenching of the fluorescence of the AuNCs. However, in the presence of AA, MnO 2 is reduced to Mn 2+ . This causes the destruction of the MnO 2 nanosheets. As a result, the fluorescence of the polyallylamine-AuNCs at 615 nm is recovered. This method for determination of AA is inexpensive, sensitive, and selective. It works in the 0.01 to 200 μM concentration range and has a 3.2 nM detection limit (for S/ N = 3).
Gold nanoclusters (AuNCs) and polyallylamine can form polyallylamine-AuNCs to enhance the orange fluorescence of AuNCs. MnO 2 nanosheets can absorb polyallylamine-AuNCs, and this results in fluorescence quenching of polyallylamine-AuNCs. Ascorbic acid (AA) can reduce MnO 2 nanosheets, in this results in the fluorescence recovery of polyallylamine-AuNCs.
研究领域:
分析化学
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纳米技术
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生物医学
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DOI
PubMed
高影响因子
ACS Sensors
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2021
·
IF 7.711
Li Xue,Nana Jin,Ruya Guo,Siyuan Wang,Wuzhen Qi,Yuanjie Liu,Yanbin Li,Jianhan Lin
In-field screening of foodborne pathogens plays an important role in ensuring food safety. Thus, a microfluidic biosensor was developed for rapid and sensitive detection of Salmonella using manganese dioxide nanoflowers (MnO2 NFs) for amplifying the biological signal, a microfluidic chip with a convergence–divergence spiral micromixer for performing automatic operations, and a smartphone app with a saturation calculation algorithm for processing the image. First, immune magnetic nanoparticles (MNPs), the sample, and immune MnO2 NFs were fully mixed and sufficiently incubated in the spiral micromixer to form MNP–bacteria–MnO2 sandwich complexes, which were magnetically captured in a separation chamber in the microfluidic chip. Then, a 3,3′,5,5′-tetramethylbenzidine (TMB) substrate was injected and catalyzed by a MnO2 NF nanomimetic enzyme on the complexes, resulting in the production of yellow catalysate. Finally, the catalysate was transferred into a detection chamber and its image was measured and processed using the smartphone app to determine the number of bacteria. This biosensor was able to detect Salmonella from 4.4 × 101 to 4.4 × 106 CFU/mL in 45 min with a detection limit of 44 CFU/mL, and has the potential to provide a promising platform for on-site detection of foodborne bacteria.
研究领域:
生物技术
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微流控技术
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食品安全
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生物传感
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纳米技术
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2020
·
IF 5.339
Ting Xiao,Shuang Wang,Mengxia Yan,Jianshe Huang,Xiurong Yang
Acetylcholinesterase (AChE) plays an essential role in biological signal transmission, the aberrant expression of which could cause diverse neurodegenerative diseases. Herein, based on the oxidase-like activity of manganese dioxide nanosheets (MnO 2 NSs), we found that MnO 2 NSs could directly oxidize thiamine into intensely fluorescent thiochrome without the need of peroxides. When AChE was introduced, acetylthiocholine could be hydrolyzed to generate thiocholine, which efficiently triggered the reduction of MnO 2 NSs into Mn 2+ , resulting in the decrease of fluorescence. Owing to the inhibiting effect of tacrine to the AChE activity, the decomposition of MnO 2 was hindered, thus leading to the fluorescence recovery. According to the above mechanism, we constructed a simple, low-cost, label-free, facile and rapid synthetic fluorescent biosensor for highly sensitive and selective detection of AChE activity and screening of its inhibitor. This biosensor obtained a good linear range from 0.02 to 1 mU/mL and an extremely low detection limit of 15 μU/mL for AChE assay, as well as a sensitive screening for tacrine and an excellent applicability in human serum samples. These results suggested that our proposed method would be potentially applied in monitoring the disease progression.
研究领域:
生物化学
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纳米技术
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分析化学
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神经科学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2021
·
IF 7.514
Qin Ouyang,Li Wang,Waqas Ahmad,Yawen Rong,Huanhuan Li,Yuqian Hu,Quansheng Chen
Carbendazim (CBZ) pesticide residues in food products have become a growing concern in recent years. Herein, a sensitive biosensor for detecting CBZ was developed based on luminescent resonance energy transfer (LRET) from aptamer labeled upconversion nanoparticles (UCNPs, donor) to manganese dioxide (MnO 2 , acceptor) nanosheets. The strong overlap between the absorption spectrum of MnO 2 and the UCNPs fluorescence emission allowed the luminescence quenching. With the addition of CBZ, it tended to bind with specific aptamers, which culminated in the UCNPs-aptamer dropping off MnO 2 nanosheets and restoring the fluorescence. A linear calibration plot between logarithmic CBZ concentration and fluorescence intensity was acquired in the range of 0.1–5000 ng·mL −1 , with a limit of detection 0.05 ng·mL −1 , indicating that the UCNPs- MnO 2 aptasensor is a rapid, sensitive and specific quantitative detection platform for CBZ. Furthermore, the precision and accuracy of the developed LRET biosensor was validated by HPLC method with no significant differences.
研究领域:
食品安全检测
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分析化学
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生物技术
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2021
·
IF 5.268
Yannan Zhao,Xinwen Zhang,Chunyan Jia,Jiangling Wu,Hua Tang,Jingchuan Shang,Chuanji Yuan,Yi Wang,Pu Zhang
As a first-line tuberculostatic drug, isoniazid (INH) plays effective and irreplaceable role in prevention and treatment of tuberculosis. In this work, a rapid and simple signal-on fluorescence approach is established for INH assay by employing a platform composed of silver nanoclusters (AgNCs) and MnO 2 nanosheets. In the proposed sensing system, strong red fluorescence of poly (methacrylic acid)-stabilized AgNCs can be greatly quenched after they attach to the surfaces of MnO 2 nanosheets. With the addition of INH, MnO 2 nanosheets are reduced to Mn 2+ and subsequently release the AgNCs, which leads to obvious fluorescence recovery again. Based on this mechanism, highly sensitive detection of INH in the range of 0.8–200 μM is realized (detection limit: 476 nM). The present strategy shows remarkable advantages including simplicity, rapidness, high sensitivity and wide detectable range. This method is also practical and comparable to high-performance liquid chromatography, which can be applied to detect INH in human urine and serum samples as well as pharmaceutical products.
研究领域:
生物化学
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医学诊断
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
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2016
·Vol. 6
·期 91
·88897-88903
·
IF 3.289
Na Wang,Xiaofeng Li,Jing Yang,Yuxia Shen,Jin Qu,Song Hong,Zhong-Zhen Yu
To enhance the recyclability while maintaining the high efficiency for the removal of organic dyes, monolithic polyurethane@reduced graphene oxide@manganese dioxide (PU@RGO@MnO2) hybrid sponge with a hierarchical structure and satisfactory flexibility is fabricated by self-assembly of RGO on a PU sponge followed by uniform coating of MnO2 nanoparticles onto RGO by means of an in situ redox reaction between RGO and KMnO4. RGO acts as an ideal substrate to accommodate MnO2 nanoparticles and prevents their aggregation, whereas the numerous hydrophilic MnO2 nanoparticles play dual roles of adsorption and catalytic degradation of methylene blue (MB) dye. The resultant hybrid sponge shows a hierarchical porous structure that provides fast transport channels and abundant active sites, benefiting the diffusion and removal of MB. By enhancing the mass transfer with the help of a micro-pump, the monolithic hybrid sponge acts as a filter for dye removal. Under the dynamic mode, the adsorption efficiency of the PU@RGO@MnO2 hybrid sponge for MB (50 ppm, 30 mL) reaches 94% after 20 min, whereas it is as low as 5% under the static mode. With the assistance of H2O2, the removal efficiency of the hybrid sponge is 96% at first time under the dynamic mode, whereas it is only 14% in the static mode. The monolithic hybrid sponge is highly efficient in adsorption and catalytic degradation of MB based on an adsorption–oxidation–desorption process. Even after being used 4 times, it still maintains excellent removal efficiency and recyclability.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
ELECTROANALYSIS
·
2017
·Vol. 30
·期 1
·137-145
·
IF 2.851
Qinglin Sheng,Xiujuan Qiao,Jianbin Zheng
3D Flower-like manganese dioxide (MnO 2 ) nanostructure with the ability of catalysis for hydrogen peroxide (H 2 O 2 ) and super large area that can support gold nanoparticles (AuNPs) with enhanced activity of electron transfer have been developed. The nanostructure of hybrids was prepared by directly mixing citric-capped AuNPs and 3-aminopropyltriethoxysilane (3-APTES)-capped nano-MnO 2 using an electrostatic adsorption strategy. The Au-MnO 2 composite was extensively characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the Brunauer-Emmett-Teller (BET) method and X-ray photoemission spectroscopy (XPS). Electrochemical properties were evaluated through cyclic voltammetry (CV) and amperometric method. The prepared sensor showed excellent electrochemical properties towards H 2 O 2 with a wide linear range from 2.5×10 −3 ∼1.39 mM and 3.89∼13.89 mM. The detection limit is 0.34 μM (S/N=3) with the sensitivities of 169.43 μA mM −1 cm −2 and 55.72 μA mM −1 cm −2 . The detection of real samples was also studied. The result exhibited that the prepared sensor can be used for H 2 O 2 detection in real samples.
研究领域:
材料科学
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分析化学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
·
IF 14.229
Yang Liu,Hao Zhou,Ranran Cao,Xingyun Liu,Pengyi Zhang,Jingjing Zhan,Lifen Liu
Volatile organic compounds (VOCs) are notorious for global air pollution. It is key to find a material with high and stable activity to catalytically oxidize VOCs at low temperatures. In this paper, benzene, as a typical VOC contaminant, could be completely oxidized on a highly efficient and moisture-resistant birnessite MnO 2 at temperatures significantly lower than the reported values in literature. The best catalyst (H-MnO 2 (30-0.2-6)) could be tailored via a facile and green process by engineering a proper combination of treatment temperature (30 °C), HNO 3 aqueous concentration (0.2 M) and treatment period (6 h). The thus-obtained MnO 2 exhibited a stable removal efficiency of ˜94% for 318 ppm of benzene under a high space velocity of 120 L·g −1 h −1 and 1.5 vol.% H 2 O at 250 °C. XRD, SEM, (HR)TEM, EDS mapping, XPS, H 2 -TPR, O 2 -TPD and pyridine adsorption IR were combined with the deliberately designed C 6 H 6 -TPD, surface oxidation reaction of benzene and CO 2 -TPD to disclose the tremendous role of acid treatment in benzene oxidation. The increased acid sites and acidity of the acid-treated surface promoted the adsorption and activation of gaseous benzene, and the lattice oxygen and surface adsorbed oxygen became more facile and reactive due to the generated active oxygen vacancies via acid treatment, these two favorable factors together with the easy desorption of reaction products resulting in the excellent performance of the acid-treated sample. Finally, the acid treatment method can be extended to most of other crystal structures of manganese dioxides except α-MnO 2 .
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 3
·594
·
IF 4.324
Chenyan Guo,Haitong Ma,Qingtong Zhang,Mingfu Li,Hongrui Jiang,Changzhou Chen,Shuangfei Wang,Douyong Min
MnO2-deposited lignin-based carbon fiber (MnO2-LCF) mats are fabricated for supercapacitor applications. LCF mats are produced from alkali lignin via electrospinning followed by stabilization and carbonization. The carbonization process is carried out at 800, 900, and 1000 °C, and the corresponding mats are denoted as MnO2-LCF-800, MnO2-LCF-900, and MnO2-LCF-1000, respectively. The LCF mats are immersed in a KMnO4solution at room temperature for 72 h to obtain MnO2-LCF mats. The scanning electron microscopy and X-ray diffraction analysis confirm the deposition of MnO2on the LCFs. The Brunauer–Emmett–Teller analysis, X-ray spectroscopy, and Raman spectroscopy reveal that MnO2-LCF-800 mat possesses a large number of mesopores and Mn vacancies as compared to MnO2-LCF-900 mat and MnO2-LCF-1000 mat. Consequently, MnO2-LCF-800 mat possesses the best electrochemical properties with a specific capacitance of 131.28 F∙g−1, an energy density of 14.77 Wh∙kg−1, and a power density of 135.01 W∙kg−1at a specific current of 0.3 A∙g−1. Hence, MnO2-LCF-800 mat shows high potential to be used as a high-performance supercapacitor.Keywords:electrospinning;lignin;carbon fiber;mno2;supercapacitor
研究领域:
材料科学
·
能源技术
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Li Xue,Fengchun Huang,Li Hao,Gaozhe Cai,Lingyan Zheng,Yanbin Li,Jianhan Lin
In this study, a sensitive immunoassay using immunomagnetic nanobeads (MNBs), manganese dioxide nanoflowers (MnO 2 NFs) and quantum dots (QDs) was developed for simultaneous detection of E. coli O157: H7 and Salmonella typhimurium. MnO 2 NFs were synthesized, functionalized and incubated with QDs to obtain [email protected] 2 nanocomposites, followed by modification with antibodies (pAbs) to obtain [email protected] 2 nanocomposites (QM NCs). Target bacteria were first conjugated with MNBs and QM NCs to form MNB-bacteria-QM complexes. Then, QDs were quickly released from the complexes using glutathione to reduce MnO 2 to Mn 2+ . Finally, fluorescent intensity at characteristic wavelength was measured by optical detector to determine target bacteria. This immunoassay could simultaneously and quantitatively detect E. coli from 1.5 × 10 1 to 1.5 × 10 6 CFU/mL with detection limit of 15 CFU/mL and Salmonella from 4.0 × 10 1 to 4.0 × 10 6 CFU/mL with detection limit of 40 CFU/mL in 2 h. The mean recovery for both bacteria in spiked chicken samples was ∼96%.
研究领域:
食品科学
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纳米技术
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生物技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Green Energy & Environment
·
2021
·
IF 8.207
Jiaqin He,Dongyun Chen,Najun Li,Qingfeng Xu,Hua Li,Jinghui He,Jianmei Lu
Improving catalytic performance is a yet still challenge in thermal catalytic oxidation. Herein, uniform mesoporous MnO 2 nanosphere-supported bimetallic Pt–Pd nanoparticles were successfully fabricated via a SiO 2 template strategy for the total catalytic degradation of volatile organic compounds at low temperature. The introduction of mesopores into the MnO 2 support induces a large specific surface area and pore size, thus providing numerous accessible active sites and enhanced diffusion properties. Moreover, the addition of a secondary noble metal can adjust the O ads /O latt molar ratios, resulting in high catalytic activity. Among them, the catalyst having a Pt/Pd molar ratio of 7:3 exhibits optimized catalytic activity at a weight hourly space velocity of 36,000 mL g −1 h −1 , reaching 100% toluene oxidation at 175 °C with a lower activation energy (57.0 kJ mol −1 ) than the corresponding monometallic Pt or non-Pt-based catalysts (93.8 kJ mol −1 and 214.2 kJ mol −1 ). Our findings demonstrate that the uniform mesoporous MnO 2 nanosphere-supported bimetallic Pt–Pd nanoparticles catalyst is an effective candidate for application in elimination of toluene.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Acta Biomaterialia
·
2021
·
IF 8.947
Xiangyu Xu,Junlin Duan,Yun Liu,Ying Kuang,Jingling Duan,Tao Liao,Ziqiang Xu,Bingbing Jiang,Cao Li
The exploration and application of hollow manganese dioxide nanoparticle (HMDN) for biosensing and biomedicine has gained significant research attention in the past decade. In this study, a type of biodegradable HMDN is prepared for multi-stimuli responsive tumor-targeted drug delivery, which was successfully loaded with doxorubicin hydrochloride (DOX). Then, the drug-loaded HMDN is functionalized with polyethyleneimine (PEI) as a gatekeeper followed by citraconic anhydride (cit) functionalized poly- L -lysine (PLL(cit)) as a charge reversal moiety successively to yield the resultant DOX@HMDN-PEI-PLL(cit) nanoparticles. In vitro study showed that DOX@HMDN-PEI-PLL(cit) exhibited a ‘‘stealthy’’ property under physiological conditions and enhanced cellular uptake activity in response to the mild acidic tumor microenvironment due to the departure of cit. In vitro release profiles proved that the decomposition of HMDN to Mn 2+ under acidic condition/high glutathione (GSH) concentration triggered the release of DOX and Fenton-like reaction for improved therapeutic effect. And Mn 2+ could also act as a T 1 -weighted magnetic resonance imaging (MRI) contrast agent. In vivo studies further proved with both the charge reversal and combined therapy properties, DOX@HMDN-PEI-PLL(cit) showed a good tumor enrichment ability and therapeutic effect with few side effects to the mice. These results demonstrate that DOX@HMDN-PEI-PLL(cit) nanoparticles are promising drug delivery systems for targeted cancer therapy. Statement of significance Traditional chemotherapy based on anticancer drugs such as doxorubicin hydrochloride (DOX) shows limited efficacy with serious side effects. We employed hollow manganese dioxide nanoparticle (HMDN) to loaded DOX and coated it with polyethyleneimine and then citraconic anhydride functionalized poly- L -lysine to endow it with a charge reversal property to obtain a multi-stimuli responsive drug delivery system named DOX@HMDN-PEI-PLL(cit). It was ‘‘stealthy’’ with low cellular uptake capability by normal cells, but could be “acid-activated” in tumors for endocytosis by cancer cells to reduce side effects. HMDN could be decomposed to Mn 2+ under acidic conditions/high glutathione concentration to release DOX intracellular. DOX and Mn 2+ catalyzed Fenton-like reaction could achieve a combined chemo-chemodynamic therapy. And Mn 2+ could be used for T 1 -weighted magnetic resonance imaging.
研究领域:
生物医学工程
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纳米技术
·
癌症治疗
·
药物递送系统
·
磁共振成像
✓ 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）