scholarly journals A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Magnetic Core-Shell Fe3O4@C/Au Nanoparticle Nanocomposite

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiao Ni ◽  
Mingwei Tian ◽  
Jun Sun ◽  
Xiaojun Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Indium Tin Oxide ◽  
Magnetic Core ◽  
Au Nanoparticle ◽  
Core Shell ◽  
Solution Ph ◽  
Catalytic Current ◽  
Magnetic Nanospheres ◽  
H2o2 Sensor

Fe3O4@C/Au nanoparticle (AuNP) nanocomposites were prepared through electrostatic adsorption of AuNPs onto PDDA-functionalized core/shell Fe3O4@C magnetic nanospheres, which had been synthesized by a facile solvothermal method. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), etc. Moreover, highly electrocatalytic activity to the reduction of hydrogen peroxide (H2O2) was also exhibited on the Fe3O4@C/AuNP-modified indium tin oxide (ITO) electrode. The effect of solution pH and the modification amount of Fe3O4@C/AuNPs on the performance of electrocatalytic H2O2 reduction was investigated. Under the optimal conditions, the catalytic current showed a linear relationship with the increase of H2O2 concentration in the range of 0.007–15 mM and a detection limit of 5 μM. The H2O2 sensor showed high selectivity for H2O2 detection, which could effectively resist the interference of ascorbic acid (AA), uric acid (UA), and citric acid (CA). Finally, the H2O2 sensor was used in the real fetal bovine serum to detect H2O2 and obtained satisfactory results with the recovery values ranging from 95.14 to 103.6%.

An ammonium molybdate deposited amorphous silica coated iron oxide magnetic core–shell nanocomposite for the efficient synthesis of 2-benzimidazoles using hydrogen peroxide

2014 ◽  
Vol 16 (6) ◽  
pp. 3160-3168 ◽  
Author(s):  
Guoyi Bai ◽  
Xingwang Lan ◽  
Xiaofang Liu ◽  
Chen Liu ◽  
Lingjuan Shi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Iron Oxide ◽  
Amorphous Silica ◽  
Magnetic Core ◽  
Ammonium Molybdate ◽  
Core Shell ◽  
Efficient Synthesis

An eco-friendly method was developed for the synthesis of 2-benzimidazoles over an Fe3O4@SiO2@(NH4)6Mo7O24 magnetic core–shell nanocomposite using hydrogen peroxide.

Synthesis of magnetic core–shell Fe3O4–Au nanoparticle for biomolecule immobilization and detection

2009 ◽  
Vol 12 (4) ◽  
pp. 1187-1196 ◽  
Author(s):  
Uğur Tamer ◽  
Yusuf Gündoğdu ◽  
İsmail Hakkı Boyacı ◽  
Kadir Pekmez
Keyword(s):  
Magnetic Core ◽  
Au Nanoparticle ◽  
Core Shell ◽  
Biomolecule Immobilization

scholarly journals Theragnostic Magnetic Core-Shell Nanoparticle as Versatile Nanoplatform for Magnetic Resonance Imaging and Drug Delivery

2021 ◽  
Vol 11 (5) ◽  
pp. 13276-13289
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Scanning Electron Microscopy ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Magnetic Core ◽  
Mri Contrast Agent ◽  
Core Shell ◽  
Mri Contrast ◽  
Scanning Electron

In this study, magnetic core-shell (MCS) nanoparticles were prepared as theragnostic potential nanoplatforms for simultaneously targeted drug delivery systems for tamoxifen and diagnosis. MCS nanoparticles were prepared in a well-shaped spherical form by the o/w emulsion method and characterized by means of dynamic light scattering (DLS), Scanning electron microscopy (SEM), Nuclear magnetic resonance (NMR), transform infrared (FT-IR) spectroscopy, and vibrating sample magnetometer (VSM). Scanning electron microscopy (SEM) indicated spherical nanostructures' formation with the final average particle size of around 80 nm. The findings proved the superparamagnetic properties of the MCS nanoparticles with relatively high-magnetization values (11.69 emu/g), which indicate that they were sensitive enough to external magnetic fields as a magnetic drug carrier. The nanoparticles showed 8.14% and 52.19% drug loading and encapsulation efficiency, respectively. MCS nanoparticles showed sustained release behavior for 120 h in the phosphate-buffered saline (PBS, pH= 7.4, 5.4) at 37 °C. The ratio between transverse and longitudinal relaxivity (r2/r1) value of the MCS nanoparticles was around 20, indicating their potential as a T2 MRI contrast agent. It can be concluded that the prepared MCS nanoparticles may serve as a promising carrier as an MRI contrast agent and targeted controlled anticancer drug delivery.

scholarly journals PEGylated Thermo-Sensitive Bionic Magnetic Core-Shell Structure Molecularly Imprinted Polymers Based on Halloysite Nanotubes for Specific Adsorption and Separation of Bovine Serum Albumin

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 536 ◽  
Author(s):  
Xiufang Li ◽  
Hui Liu ◽  
Zhiwei Deng ◽  
Wenqing Chen ◽  
Tianhao Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bovine Serum Albumin ◽  
Adsorption Capacity ◽  
Molecularly Imprinted Polymers ◽  
Shell Structure ◽  
Magnetic Core ◽  
Core Shell ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Core Shell Structure

Novel PEGylated thermo-sensitive bionic magnetic core-shell structure molecularly imprinted polymers (PMMIPs) for the specific adsorption and separation of bovine serum albumin (BSA) were obtained via a surface-imprinting technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA), and specific surface area (BET), were adopted to demonstrate that novel PMMIPs were successfully synthesized. Subsequently, the prepared PMMIPs were used as the extractor for BSA and were combined with magnetic solid-phase extraction. The concentrations of BSA were detected by UV-vis spectrophotometry at 278 nm. The maximum adsorption capacity of the PMMIPs was 258 mg g−1, which is much higher than that of non-imprinted polymer (PMNIPs). PMMIPs showed favorable selectivity for BSA against reference proteins, i.e., bovine hemoglobin, ovalbumin and lysozyme. PMMIPs were further used to recognize BSA in protein mixtures, milk, urine and sewage, these results revealed that approximately 96% of the ideal-state adsorption capacity of PMMIPs for BSA was achieved under complicated conditions. Regeneration and reusability studies demonstrated that adsorption capacity loss of the PMMIPs was not obvious after recycling for four times. Facile synthesis, excellent adsorption property and efficient selectivity for BSA trapping are features that highlight PMMIPs as an attractive candidate for biomacromolecular purification.

scholarly journals Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

2014 ◽  
Vol 5 ◽  
pp. 466-475 ◽  
Author(s):  
M Hennes ◽  
A Lotnyk ◽  
S G Mayr
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnetic Core ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Gas Condensation ◽  
Pulsed Dc ◽  
Transmission Electron ◽  
Core Shell Nanoparticles ◽  
Kinetic Gas Theory

Magnetically anisotropic as well as magnetic core–shell nanoparticles (CS-NPs) with controllable properties are highly desirable in a broad range of applications. With this background, a setup for the synthesis of heterostructured magnetic core–shell nanoparticles, which relies on (optionally pulsed) DC plasma gas condensation has been developed. We demonstrate the synthesis of elemental nickel nanoparticles with highly tunable sizes and shapes and Ni@Cu CS-NPs with an average shell thickness of 10 nm as determined with scanning electron microscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. An analytical model that relies on classical kinetic gas theory is used to describe the deposition of Cu shell atoms on top of existing Ni cores. Its predictive power and possible implications for the growth of heterostructured NP in gas condensation processes are discussed.

Preparation and Characterization of Mno.5Zno.5Fe2O4 @Au Composite Nanoparticles and its Anti-Tumor Effect on Glioma Cells

2011 ◽  
Vol 138-139 ◽  
pp. 907-913
Author(s):  
Yun Tao Li ◽  
Jing Liu ◽  
Li Wang ◽  
Jia Zhang ◽  
Zi Yu Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Au Nanoparticles ◽  
Glioma Cells ◽  
Trisodium Citrate ◽  
Average Diameter ◽  
Composite Nanoparticles ◽  
Au Nanoparticle ◽  
Core Shell

To explore the preparation method and characters of a new gold nanoshells on maganese-zinc ferrite (Mno.5Zno.5Fe2O4@Au) composite nanoparticles. Mno.5Zno.5Fe2O4@Au nanoparticles with core/shell structure were synthesized by reduction of Au3+ with trisodium citrate in the presence of Mno.5Zno.5Fe2O4 magnetic nanoparticles (MZF-NPs) prepared by improved co-preciption with the character of superparamagnetism and detected by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrometry (EDS) and Marven laser particle size analyzer.Thermodynamic test was used to observe temperature change of various doses of Mno.5Zno.5Fe2O4@Au nanoparticles. The cytotoxicity of the Mno.5Zno.5Fe2O4@Au composite nanoparticles in vitro was tested by the MTT assay. The therapeutic effect of Mno.5Zno.5Fe2O4@Au composite nanoparticles combined with magnetic fluid hyperthermia (MFH) on human glioma cells were evaluated in vitro by an MTT assay.The results indicated that the Mno.5Zno.5Fe2O4@Au composite nanoparticles were prepared successfully. The core/shell particles were spherical with exact average diameter of them was 66.9nm.EDS showed each Mno.5Zno.5Fe2O4@Au nanoparticle contained Mn, Zn, Fe, O and Au elements, and this proved Au had successfully attached to Mn0.5Zn0.5Fe2O4.The result of thermodynamic test showed that Mno.5Zno.5Fe2O4@Au composite nanoparticles could serve as a heating source under alternating magnetic field (AMF) exposure leading to reach their steady temperature (40-45°C). Moreover, Mno.5Zno.5Fe2O4@Au composite nanoparticles didn’t show cytotoxicity in vitro. The therapeutic result reveals that Mno.5Zno.5Fe2O4@Au composite nanoparticles can significantly inhibit the growth of glioma cells.The conclusion was that the self-prepared Mno.5Zno.5Fe2O4@Au composite nanoparticles had strong magnetic responsiveness and good power absorption capabilities in the high frequency AMF,then they could suggested to be useful for glioma hyperthemia. Mno.5Zno.5Fe2O4 @Au composite nanoparticles can not only be directed to tumor region in a given magnetic field more exactly but also produce marked thermotherapy.

Heterogeneous Fenton Catalytic Removal of Organic Pollutant in Aqueous Solution by using Coal Gangue as a Catalyst

2019 ◽  
Vol 12 (4) ◽  
pp. 312-325
Author(s):  
Jiwei Zhang ◽  
Jingjing Xu ◽  
Shuaixia Liu ◽  
Baoxiang Gu ◽  
Feng Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Removal Rate ◽  
Organic Pollutant ◽  
Coal Gangue ◽  
Ion Leakage ◽  
Heterogeneous Fenton ◽  
Solution Ph ◽  
X Ray

Background: Coal gangue was used as a catalyst in heterogeneous Fenton process for the degradation of azo dye and phenol. The influencing factors, such as solution pH gangue concentration and hydrogen peroxide dosage were investigated, and the reaction mechanism between coal gangue and hydrogen peroxide was also discussed. Methods: Experimental results showed that coal gangue has the ability to activate hydrogen peroxide to degrade environmental pollutants in aqueous solution. Under optimal conditions, after 60 minutes of treatment, more than 90.57% of reactive red dye was removed, and the removal efficiency of Chemical Oxygen Demand (COD) up to 72.83%. Results: Both hydroxyl radical and superoxide radical anion participated in the degradation of organic pollutant but hydroxyl radical predominated. Stability tests for coal gangue were also carried out via the continuous degradation experiment and ion leakage analysis. After five times continuous degradation, dye removal rate decreased slightly and the leached Fe was still at very low level (2.24-3.02 mg L-1). The results of Scanning Electron Microscope (SEM), energy dispersive X-Ray Spectrometer (EDS) and X-Ray Powder Diffraction (XRD) indicated that coal gangue catalyst is stable after five times continuous reuse. Conclusion: The progress in this research suggested that coal gangue is a potential nature catalyst for the efficient degradation of organic pollutant in water and wastewater via the Fenton reaction.

Indium–tin oxide film electrode as catalytic amperometric sensor for hydrogen peroxide

The Analyst ◽  
1995 ◽  
Vol 120 (10) ◽  
pp. 2579-2583 ◽  
Author(s):  
Xiaohua Cai ◽  
Božidar Ogorevc ◽  
Gabrijela Tavčar ◽  
Joseph Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Oxide Film ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Amperometric Sensor ◽  
Film Electrode
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