SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Yingfeng Qin,Gaojie Ye,Hao Liang,Ming Li,Jingjin Zhao
It is highly desirable to develop a simple, efficient and sensitive strategy for organophosphorus pesticides (OPs) in both environment pollution and human health. Herein, a novel amplified fluorescence polarization (FP) biosensor was established for highly sensitive detection of OPs using MnO 2 nanosheets as the signal enhancer. In this system, OPs can suppress the activity of acetylcholinesterase (AChE) efficiently, blocking the hydrolysis reaction of acetylthiocholine (ATCh) to generate thiocholine (TCh) by AChE. TCh can lead the decomposition of MnO 2 nanosheets to manganese ions. So, without the influence of TCh, MnO 2 nanosheets can maintain its original shape and form a stable complex with FAM-DNA, which greatly enhanced the FP signal. This method can tremendously improve the sensitivity of FP with a detection limit of 0.01 ng/mL for diazinon. In addition, it was also applicable to determine other four OPs and investigate the level of diazinon in real water samples. Consequently, the proposed approach provides a new promising platform for detection of OPs and is expected to be used in application of environmental monitoring.
研究领域:
环境科学
·
分析化学
·
生物传感
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产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 8
·1-10
·
IF 5.479
Ma Zhangyan,Wu Tengteng,Li Peipei,Liu Meiling,Huang Si,Li Haitao,Zhang Youyu,Yao Shouzhuo
A fluorimetric and colorimetric method is described for the determination of glutathione (GSH) and silver (I). It is based on the use of MnO 2 nanosheets that were prepared by solution mixing and exfoliation. They display oxidase-mimicking activity and can catalyze the oxidation of o-phenylenediamine (OPD) to form yellow 2,3-diaminophenazine (DAP) with an absorption maximum at 410 nm. DAP also has a yellow fluorescence (with a peak at 560 nm). The MnO 2 nanosheets can be rapidly reduced to Mn 2+ by GSH. This reduces the efficiency of the oxidase mimic MnO 2 and causes a decrease in fluorescence and absorbance intensity. However, on addition of Ag + , a complex is formed with GSH. It prevents the destruction of MnO 2 nanosheets so that the enzyme mimicking activity is retained. A dual-method for the determination of GSH and Ag(I) was developed. It has excellent sensitivity for GSH with lower detection limits of 62 nM (fluorimetric) and 0.94 μM (colorimetric). The respective data for Ag(I) are 70 nM and 1.15 μM. The assay was successfully applied to the determination of GSH and Ag(I) in spiked serum samples.
Schematic presentation of a method for colorimetric and fluorometric determination of glutathione (GSH) and silver(I). MnO 2 nanosheets are reduced to Mn(II) by GSH. This reduces the enzyme-mimicking activity of MnO 2 nanosheets and causes a decrease in fluorescence and absorbance. On addition of Ag(I), the enzyme-like activity is increasingly retained. A decrease in fluorescence and absorbance is not observed any longer.
研究领域:
分析化学
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生物医学工程
·
材料科学
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DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2025
·
IF 4.6
Menglu An,Weiying Wang,Jingguo Li,Shaokui Cao,Yingliang Liu,Jun Shi
MnO 2 nanosheets have attracted extensive attention in the field of photothermal therapy due to their excellent pH/glutathione (GSH) responsiveness. In this study, MoS 2 @gold nanorods (AuNRs)/polydopamine (PDA)@MnO 2 (400–500 nm) nanocomposites with controllable drug release property were prepared by covering MnO 2 nanosheets around near-infrared (NIR) responsive MoS 2 @AuNRs (100–200 nm) via in-situ redox reaction. The large surface area and strong negative charge of MnO 2 nanosheets ensured that MoS 2 @AuNRs/PDA@MnO 2 had a high loading efficiency of 92.44 % for doxorubicin hydrochloride (DOX). MoS 2 @AuNRs/PDA@MnO 2 revealed significant NIR/pH/GSH triple-responsive drug release properties owing to the synergistically enhanced NIR photothermal-response of MoS 2 @AuNRs (61.10 % of photothermal conversion efficiency) and the reaction between MnO 2 and GSH in weakly acidic media. In addition, in vitro cell viability results confirmed that MoS 2 @AuNRs/PDA@MnO 2 could efficiently kill tumor cells under the dual action of acidic media and NIR laser. This study develops a novel nanocarrier with NIR/pH/GSH triple-responsive drug delivery capability, which has broad applications in photothermal therapy and intelligent drug delivery.
研究领域:
生物医学工程
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纳米医学
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肿瘤治疗
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yaru Zhang,Zhenchao Li,Xin Zhang,Mingyang Wang,Ziting Lin,Ying Zhang,Aihua Liu
Nanozymes have favorable activity and good stability, which are potential alternatives to natural enzymes and widely applied in biosensing. However, nanozymes based electrochemical sensors are fewer, because many nanozymes are not easy to form efficient electrocatalytic interface and experience interference from the possible oxidizable species. Herein, ultrathin MnO 2 nanosheets (MnO 2 NSs) were synthesized by reduction of KMnO 4 in acidic environment by chemical precipitation method. The MnO 2 NSs show excellent catechol oxidase mimicking activity. The steady-state kinetics of MnO 2 NSs shows a higher V max of 3.441 µM s −1 . Additionally, the catalytic mechanism is that in the presence of oxygen, catechol or its analogues are oxidized to quinone or quinoids, while oxygen is reduced to H 2 O. Afterwards, the possible mechanism of dopamine (DA) at MnO 2 NSs-modified electrode is investigated. DA is first catalytically oxidized to dopamine quinone (DQ) by MnO 2 NSs based catechol oxidase , which further undergoes irreversible electrochemical reduction to DA involving two protons and two electrons transfer during the process. On the basis of this, a selective and ultrasensitive amperometric detection of DA at 0.0 V (vs. SCE) was explored, which have two linear parts, 0.01–20 μM and 20–100 μM DA with the LOD of 4.1 nM (S/N = 3). Most importantly, the presence of oxidizable species including ascorbic acid, uric acid and cysteine may coexist with DA in biological systems do not exhibit any appreciable interference. The as-proposed method was applicable to detect DA in human serum samples with good satisfactory accuracy and recovery. This research casts prospect to apply nanozymes for electrochemical sensor with excellent analytical performance.
研究领域:
生物化学
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分析化学
·
材料科学
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 9
·1-11
·
IF 6.232
Ye Mingshu,Lin Bixia,Yu Ying,Li He,Wang Yumin,Zhang Li,Cao Yujuan,Guo Manli
By using graphene quantum dots (GQDs) and o -phenylenediamine (OPD), a ratiometric fluorescence probe was designed for the highly sensitive and selective detection of AChE. GQDs with strong fluorescence were synthesized by the one-step hydrothermal method. The optimal emission wavelength of GQDs was 450 nm at the excitation wavelength of 375 nm. MnO 2 nanosheets with a wide absorption band of 300–600 nm were prepared at room temperature. Because of the extensive overlap between the absorption spectrum of MnO 2 nanosheets and the excitation and emission spectra of GQDs, the fluorescence of GQDs at 450 nm was efficiently quenched by the inner-filter effect. Meanwhile, due to the peroxidase-like activity of MnO 2 nanosheets, OPD was catalytically oxidized to 2,3-diaminophenazine (oxOPD), a yellow fluorescent substance with a new emission peak at 572 nm. When AChE was present, the substrate acetylthiocholine (ATCh) was hydrolyzed to thiocholine (TCh) that is capable of decomposing MnO 2 nanosheets. Therefore, the quench of GQDs and the oxidation of OPD by MnO 2 nanosheets were suppressed, resulting in the fluorescence recovery of GQDs at 450 nm, while the fluorescence decrease of oxOPD at 572 nm. Utilizing the fluorescence intensity ratio F 450 /F 572 as the signal readout, the ratiometric fluorescence method was established to detect AChE activity. The ratio F 450 /F 572 against the AChE concentration demonstrated two linear relationships in the range 0.1–2.0 and 2.0–4.5 mU mL −1 with a detection limit of 0.09 mU mL −1 . The method was applied to the detection of positive human serum samples and the analysis of the inhibitor neostigmine. Due to the advantages of high sensitivity, favorable selectivity, and strong anti-interference, the method possesses an application prospect in clinical diagnosis of AChE and the screening of inhibitors.
Schematic presentation of a ratiometric fluorescence method for the detection of acetylcholinesterase (AChE). The fluorescence of graphene quantum dots (GQDs) is quenched and o -phenylenediamine (OPD) is oxidized to generate fluorescent product 2,3-diaminophenazine (oxOPD) by MnO 2 nanosheets. When AChE is present, acetylthiocholine iodide (ATCh) is hydrolyzed to thiocholine (TCh) with reducibility for decomposing MnO 2 nanosheets. Due to the decomposition of MnO 2 nanosheets, the quenching of GQDs and oxidation of OPD are suppressed. The fluorescence of GQDs at 450 nm is enhanced, while the fluorescence of oxOPD at 572 nm is reduced. The fluorescence intensity ratio F 450 /F 572 is used to establish the ratiometric fluorescence method for AChE activity.
研究领域:
生物化学
·
分析化学
·
医学诊断
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 46
·期 3
·1120-1126
·
IF 3.591
Wenwen Liu,Qing Kang,Pengcheng Wang,Feimeng Zhou
The ratiometric fluorescence immunoassay is known as a spectrofluorimetric variant for the sensitive and quantitative analyses of biomarkers. However, there are few comparative studies between it and the traditional, single-wavelength-based immunoassay. In this work, a ratiometric fluorescence immunoassay was designed via fluorescence resonance energy transfer (FRET) in a system comprising MnO2 nanosheets, o-phenylenediamine (OPD), and fluorescent carbon nanodots (FCNs). The MnO2 nanosheet oxidizes OPD, producing a fluorescence peak at 580 nm, while FCNs exhibit a fluorescence peak at 490 nm. Under the effect of FRET, the fluorescence at 580 nm increases significantly while the fluorescence at 490 nm is reduced. The FRET effect was confirmed by our fluorescence lifetime measurements. We optimized the experimental conditions that include solution pH, OPD concentration, and reaction time. By electrostatically coating the MnO2 nanosheets with antibody molecules and using the resultant materials as a detection probe, the ratiometric fluorescence sensing was extended to the detection of alpha fetoprotein (AFP) in human serum samples on a 96-well titer plate. Our ratiometric fluorescence immunoassay possesses a good dynamic range (from 0.14 to 130.43 pM). The detection limit was estimated to be 0.13 pM (0.009 ng mL−1), which is 7.6-fold lower than that of the single-wavelength-based immunoassay. The measurement results of serum samples from healthy and patient donors are highly comparable to those measured by chemiluminescence for the same donors, demonstrating the viability for serological assays of important cancer markers.
研究领域:
生物化学
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医学检验
·
纳米技术
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产品关联
DOI
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
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产品关联
DOI
PubMed
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
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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
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产品关联
DOI
高影响因子
Analytical Methods
·
2021
·Vol. 13
·期 46
·5542-5548
·
IF 2.896
Xinfa Cai,Meijuan Liang,Fei Ma,Sherif Ramzy Mohamed,Amira Abdel Goda,Dawood H. Dawood,Li Yu,Peiwu Li
A direct competitive nanozyme-linked immunosorbent assay (dcNLISA) based on MnO2 nanosheets (MnO2 NSs) as a nanozyme label was developed for the highly sensitive determination of fumonisin B1 (FB1). MnO2 NS-labeled fumonisin B1-bovine serum albumin was easily synthesized as a competing antigen for the dcNLISA. And color changes derived from the MnO2–3,3′,5,5′-tetramethylbenzidine (TMB) system were exploited as the output signals of the dcNLISA. Several experimental parameters including the concentrations of the coating antibody, pH values, ionic strength and methanol concentration were optimized. Under the optimal conditions, the proposed method demonstrated a linear range (1.17–20.74 ng mL−1) with a reliable correlation coefficient (R2 = 0.9989), a satisfactory limit of detection (0.63 ng mL−1) and high selectivity for the detection of FB1. The recoveries of FB1 in spiked corn and wheat samples were in the range of 85.31–108.16% with coefficients of variation (CVs) ranging from 6.14% to 9.23%. Meanwhile, the testing results showed good consistency (R2 = 0.9892) between the developed dcNLISA and the reference method, liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS) method. The proposed method was proven to be simple, sensitive, cost-effective and reliable for the screening of FB1 in cereals.
研究领域:
食品科学
·
分析化学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Nan Jiang,Peng Li,Shihao Sun,Wei Wei
Since 5-hydroxymethylfurfural (HMF) becomes a neo-forming contaminant with latent harm to human health, development of new method for highly sensitive detection of HMF is extremely desirable. Herein, a novel ratiometric fluorescence sensor based on strand displacement reaction and magnetic separation was designed for sensitive and selective detection of HMF with the help of MnO 2 nanosheets . The aldehyde-functionalized DNA (S0–CHO) and HMF competed for binding to amino-functionalized magnetic beads (NH 2 -MBs). Then, S0–CHO was collected from supernatant by magnetic separation. In the presence of HMF, the obtained S0–CHO induced the formation of T-shaped DNA by strand displacement reaction (SDR), lighting the fluorescence of FAM. In the absence of HMF, no S0–CHO was present to ignite T-shaped DNA. In this situation, fluorescence of Cy5 was turned on. Thus, a ratiometric fluorescence sensor for high-sensitive detection of HMF was developed. The sensor has a wide linear range from 5 nM to 5 μM. It also exhibited high selectivity against other potential interfering substances. It has been successfully applied to analyze HMF in food samples. The method has potential to be expanded to detect other molecules containing aldehyde groups and further be applied in food safety, environment and other fields.
研究领域:
生物化学
·
分析化学
·
食品安全
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 45
·28644-28648
·
IF 3.906
Mengxin Zhao,Yang Tao,Wei Huang,Yi He
Although the enzyme-like activities of MnO2 nanosheets have been investigated, effective strategies for modulating their activities are still lacking. Herein, inspired by the pH-dependent activity of natural enzymes, we demonstrate that the oxidase-like activities of the MnO2 nanosheets are pH switchable and reversible. The MnO2 nanosheets show oxidase-like activities in an acidic medium, which can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to form blue oxidized TMB (oxTMB), while the corresponding activities are greatly weakened under alkaline conditions. The reaction mechanism is attributed to the fact that the MnO2 nanosheets can be transformed into hexagonal Na4MnO4 with a low reaction activity in an alkaline environment. Using the pH switchable oxidase-like activities of the MnO2 nanosheets and other reaction processes, we construct a visual three-input molecular majority logic gate with a single-vote veto function. In addition, an OR-INH cascade logic circuit is successfully realized as well.
研究领域:
生物化学
·
纳米生物学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
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