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1.
A novel nanocomposite electrode based on hierarchical 3D porous MnO2?TiO2 for the application in hydrogen peroxide (H2O2) sensors has been explored. This electrode was fabricated by growing TiO2 cross‐linked nanowires on a commercial fluorine tin oxide (FTO) glass via a hydrothermal process and subsequent deposition of 3D honeycomb‐like MnO2 nanowalls using an electrodeposition method (denoted as 3D MNS‐TNW@FTO). The obtained 3D MNS‐TNW@FTO electrode was characterized by scanning electron microscopy (SEM), Raman spectroscopy, X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). Based on such a unique 3D porous framework and the existence of MnO2, the electrode demonstrates a good performance in the detection of H2O2, with two linear ranges from 9.8 to 125 μM and 125 μM–1.0 mM, a good selectivity of 8.02 μA mM?1 cm?2, and a low detection limit of 4.5 μM. In addition, the simplicity of the developed low‐cost fabrication process provides an efficient method for the mass production of electrocatalytical MnO2?TiO2 nanocomposites on commercial FTO glass for H2O2 sensing applications and can be adapted for other electrochemical sensors for various biochemical targets. It thus is beneficial for the practical usage in bioanalysis.  相似文献   

2.
The nanocomposites of Ag nanoparticles supported on Cu2O were prepared and used for fabricating a novel nonenzymatic H2O2 sensor. The morphology and composition of the nanocomposites were characterized using the scanning electron microscope (SEM), transmission electron microscope (TEM), energy‐dispersive X‐ray spectrum (EDX) and X‐ray diffraction spectrum (XRD). The electrochemical investigations indicate that the sensor possesses an excellent performance toward H2O2. The linear range is estimated to be from 2.0 μM to 13.0 mM with a sensitivity of 88.9 μA mM?1 cm?2, a response time of 3 s and a low detection limit of 0.7 μM at a signal‐to‐noise ratio of 3. Additionally, the sensor exhibits good anti‐interference.  相似文献   

3.
A novel non‐enzymatic sensor based on Ag/MnOOH nanocomposites was developed for the detection of hydrogen peroxide (H2O2). The H2O2 sensor was fabricated by immobilizing Ag/MnOOH nanocomposites on a glassy carbon electrode (GCE). The morphology and composition of the sensor surface were characterized using scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, transmission electron microscopy and X‐ray diffraction spectroscopy. The electrochemical investigation of the sensor indicates that it possesses an excellent electrocatalytic property for H2O2, and could detect H2O2 in a linear range from 5.0 µM to 12.8 mM with a detection limit of 1.5 µM at a signal‐to‐noise ratio of 3, a response time of 2 s and a sensitivity of 32.57 µA mM?1 cm?2. Additionally, the sensor exhibits good anti‐interference. The good analytical performance, low cost and straightforward preparation method made this novel electrode material promising for the development of effective non‐enzymatic H2O2 sensor.  相似文献   

4.
A sonochemical method has been successfully used to synthesize MnO2/MWNTs nanocomposites. The structure and nature of the resulting MnO2/MWNTs composite were characterized by scanning electron microscopy (SEM), energy‐dispersive X‐ray diffraction (EDX), X‐ray photoelectron spectroscopy (XPS).The results show that the sonochemically synthesized MnO2 nanoparticles were homogeneously dispersed on the modified MWNT surfaces. The performance of the MnO2/MWNTs nanocomposites modified electrode was characterized using cyclic voltammetry (CV) and Nyquist plots. The electrode exhibits efficient electron transfer ability and high electrochemical response towards hydrazine. This may be attributed to the small particle size, high dispersion of MnO2 particles. The fabricated hydrazine sensor showed a wide linear range of 5.0×10?7–1.0×10?3 M with a response time less than 5 s and a detection limit of 0.2 μM. Taking the advantage of the unique properties of both MWNTs and MnO2, it would greatly broaden the applications of MWNTs and MnO2.  相似文献   

5.
《Electroanalysis》2018,30(1):137-145
3D Flower‐like manganese dioxide (MnO2) nanostructure with the ability of catalysis for hydrogen peroxide (H2O2) 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‐MnO2 using an electrostatic adsorption strategy. The Au‐MnO2 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 H2O2 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 H2O2 detection in real samples.  相似文献   

6.
MnO2/graphene nanocomposites with different morphologies were synthesized and the petal‐shaped nanosheet MnO2/graphene composite was developed as an electrode material for nonenzymatic hydrogen peroxide (H2O2) sensor. The morphology, structure, composition, and hydrophilicity of the resulting products were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and the contact angle tests. In addition, the fabricated MnO2/graphene composites could be used as catalysts for the electrochemical oxidation of H2O2. Cyclic voltammogram (CV) experiments indicated that MnO2/graphene‐modified electrode showed good electrocatalytic activity towards both the oxidation and reduction of H2O2 in a neutral environment. Amperometric response results illustrated that this nonenzymatic sensor had excellent anti‐interference ability and displayed two linear ranges from 10 to 90 µM and from 0.2 to 0.9 mM with a detection limit of 2 µM.  相似文献   

7.
In this study, magnetite nanorods stabilized on polyaniline/reduced graphene oxide (Fe3O4@PANI/rGO) was synthesized via a wet‐reflux strategy. The possible formation of Fe3O4@PANI/rGO was morphologically and structurally verified by field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FT‐IR) spectroscopy, Raman spectroscopy, X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). Furthermore, the thermal stability of Fe3O4@PANI/rGO was measured by a thermogravimetric analyzer (TGA); the composite had good thermal stability owing to the ceramic nature of Fe3O4. The Fe3O4@PANI/rGO has been applied as a potential sensing platform for electrochemical detection of hydrogen peroxide (H2O2). By the combined efforts of extended active surface area, active carbon support, more catalytic active sites and high electrical conductivity, the Fe3O4@PANI/rGO exhibited an improved performance toward the non‐enzymatic detection of H2O2 in 0.5 M KOH with a fast response time (5 s), high sensitivity (223.7 μA mM?1 cm?2), low limit of detection (4.45 μM) and wide linear range (100 μM–1.5 mM). Furthermore, the fabricated sensor exhibited excellent recovery rates (94.2–104.0 %) during real sample analysis.  相似文献   

8.
A novel composite material of copper (I) oxide at manganese (IV) oxide (Cu2O@MnO2), was synthesized and applied for modification on the glassy carbon electrode (GCE) surface (Cu2O@MnO2/GCE) as a hydrogen peroxide (H2O2) sensor. The composite material was characterized regarding its structural and morphological properties, using field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The Cu2O@MnO2/GCE showed an excellent electrocatalytic response to the oxidation of H2O2 which provided a 0.56 s?1 charge transfer rate constant (Ks), 1.65×10?5 cm2 s?1 diffusion coefficient value (D), 0.12 mm2 electroactive surface area (Ae) and 1.04×10?8 mol cm?2 surface concentration ( ). At the optimal condition, the constructed sensor exhibited a wide linear range from 0.5 μM to 20 mM with a low limit of detection (63 nM, (S/N=3) and a good sensitivity of 256.33 μA mM?1 cm?2. It also presented high stability (ΔIresponse±15 %, n=100), repeatability (1.25 %RSD, n=10) and reproducibility (3.55 %RSD, n=10). The results indicated that the synthesized Cu2O@MnO2 was successfully used as a new platform for H2O2 sensing.  相似文献   

9.
A poly(2‐aminophenylbenzimidazole)/gold nanoparticles (P2AB/AuNPs) coated disposable pencil graphite electrode (PGE) was fabricated as an enzyme‐free sensor for the H2O2 determination. P2AB/AuNPs and P2AB were successfully synthesized electrochemically on PGE in acetonitrile for the first time. The coatings were characterized by scanning electron microscopy, X‐ray diffraction spectroscopy, Energy‐dispersive X‐ray spectroscopy, Surface‐enhanced Raman spectroscopy, and UV‐Vis spectroscopy. AuNPs interacted with P2AB as carrier enhances the electrocatalytic activity towards reduction of H2O2. The analytical performance was evaluated in a 100 mM phosphate buffer solution at pH 6.5 by amperometry. The steady state current vs. H2O2 concentration is linear in the range of 0.06 to 100 mM (R2=0.992) with a limit of detection 3.67×10?5 M at ?0.8 V vs. SCE and no interference is caused by ascorbic acid, dopamine, uric acid, and glucose. The examination for the sensitive determination of H2O2 was conducted in commercially available hair oxidant solution. The results demonstrate that P2AB/AuNPs/PGE has potential applications as a sensing material for quantitative determination of H2O2.  相似文献   

10.
In this article, we report on the synthesis and new employment of magnetic nickelferrite oxide nanoparticles decorated reduced graphene oxide (NiFe2O4/rGO) to electrochemically sensing of flutamide. The preparation of this electrocatalyst was first assessed using various analytical instrumental techniques including FT‐IR spectroscopy, X‐ray diffraction spectroscopy, energy‐dispersive X‐ray spectroscopy, and field emission scanning and transmission electron microscopy. Besides, its electrochemical performance was investigated utilizing some electrochemical methods such as cyclic and differential pulse voltammetry, and also electrochemical impedance spectroscopy. The findings of this research are especially relevant for sensing flutamide in aqueous and biological samples. At the optimized conditions, the electrochemical sensor showed a linear range of 0.24–40.0 μmol L?1, the detection limit of 0.05 μmol L?1 flutamide, calibration sensitivity of 1.016 μA/μmol L?1, and repeatability and reproducibility of 1.7 % and 4.1 %, respectively. The selectivity of the method was investigated in the presence of ions, and species can generally exist in the biological medium. The resulting data of the present work represented that this type of magnetic nanocomposites is suitable for selective detection of flutamide in real samples of plasma and urine. The recoveries obtained for flutamide analyses represented lower than 5.0 percent of relative error in these real samples.  相似文献   

11.
A novel flower like 3D nickel/manganese dioxide (Ni/MnO2) nanocomposite was synthesized by a kind of simple electrochemical method and the formation mechanism of flower like structure was also researched. In addition, morphology and composition of the nanocomposite were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS). Then the Ni/MnO2 nanocomposites were applied to fabricate electrochemical non‐enzymatic glucose sensor. The electrochemical investigation for the sensor indicated that it possessed an excellent electrocatalytic property for glucose, and could applied to the quantification of glucose with a linear range from 2.5×10?7 to 3.5×10?3 M, a sensitivity of 1.04 mA mM?1 cm?2, and a detection limit of 1×10?7 M (S/N=3). The proposed sensor also presented attractive features such as interference‐free, and long‐term stability. The present study provided a general platform for the one‐step synthesis of nanomaterials with novel structure and can be extended to other optical, electronic and magnetic nanocompounds.  相似文献   

12.
Here, an electrochemical sensor based on CeO2‐SnO2/Pd was prepared and used for highly selective and sensitive determination of nitrite in some real samples. This nanocomposite was characterized by various methods like X‐ray photoelectron spectroscopy, X‐ray diffraction, energy dispersive spectroscopy, Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. The electrochemical behavior of the sensor was evaluated by cyclic voltammetry. The results showed excellent catalytic property of the nanocomposite as a an electrocatalyst for nitrite oxidation. In the following, the experimental parameters affecting the analytical signal for nitrite were optimized. Under the optimal conditions, the limit of detection and sensitivity of the sensor were calculated as 0.10 μM and 652.95 μA.mM?1.cm?2, respectively. Also, the response of the sensor was linear in the range of 0.36 to 2200 μM of nitrite. Finally, some of the inherent features of the sensor such as repeatability, reproducibility and stability were examined after evaluation of the sensor selectivity in the presence of several interfering species.  相似文献   

13.
The study presents a novel paracetamol (PA) sensor based on Pd nanoparticles (PdNPs) deposited on carboxylated graphene oxide (GO?COOH) and nafion (Nf) modified glassy carbon electrode (GCE). The morphologies of the as prepared composites were characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and fourier transform infrared spectroscopy (FTIR). The experimental results demonstrated that Nf/GO?COOPd displayed excellent electrocatalytic response to the oxidation PA. The linear range was 0.04–800 μM for PA with limit of detection of 0.012 μM and excellent sensitivity of 232.89 μA mM?1 cm?2. By considering the excellent performance of Nf/GO?COOPd composite such as wider linear range, lower detection, better selectivity, repeatability, reproducibility, and storage stability, the prepared composite, especially GO?COOH support, with satisfactory electrocatalytic properties was a promising material for the modification of electrode material in electrochemical sensor and biosensor field.  相似文献   

14.
Functionalized‐multiwall carbon nanotubes decorated with redox active copper nanoparticles have been fabricated for sensitive enzyme‐less H2O2 detection. The new nanocomposite was characterized by Transmission electron microscopy, energy dispersive X‐ray analysis and cyclic voltammetry. The response of the modified electrode to H2O2 was examined using amperometry at ?0.45 V vs. Ag/AgCl in a buffer solution at pH 10.0. The developed sensor displayed linear concentration ranges of 0.5–10.0 and 10.0–10000.0 µmol L?1 with a detection limit of 0.3 µmol L?1. The proposed sensor displayed good selectivity for H2O2 detection in the presence of common interferences such as ascorbic acid.  相似文献   

15.
Co3O4/graphene oxide (GO) nanocomposites were successfully prepared by a depositing‐decomposition method. The as‐prepared samples were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Cyclic voltammetry (CV) was used to evaluate the electrochemical response of a glass carbon electrode (GCE) modified with Co3O4/GO nanocomposite towards glucose. Compared with the Co3O4/GCE, the Co3O4/GO/GCE exihibits higher electrocatalytic activity due to the synergistic effects of electrocatalytic ability of Co3O4 and large surface of GO. The Co3O4/GO/GCE was applied for glucose detection in alkaline solution. The linear current response range of glucose on Co3O4/GO/GCE covered the range from 9 × 10?5 to 6.03 × 10?3 M, with a detection limit of 5.2 × 10?7 M (S/N = 3).  相似文献   

16.
A novel nonenzymatic H2O2 sensor based on a palladium nanoparticles/graphene (Pd‐NPs/GN) hybrid nanostructures composite film modified glassy carbon electrode (GCE) was reported. The composites of graphene (GN) decorated with Pd nanoparticles have been prepared by simultaneously reducing graphite oxide (GO) and K2PdCl4 in one pot. The Pd‐NPs were intended to enlarge the interplanar spacing of graphene nanosheets and were well dispersed on the surface or completely embedded into few‐layer GN, which maintain their high surface area and prevent GN from aggregating. XPS analysis indicated that the surface Pd atoms are negatively charged, favoring the reduction process of H2O2. Moreover, the Pd‐NPs/GN/GCE could remarkably decrease the overpotential and enhance the electron‐transfer rate due to the good contact between Pd‐NPs and GN sheets, and Pd‐NPs have high catalytical effect for H2O2 reduction. Amperometric measurements allow observation of the electrochemical reduction of H2O2 at 0.5 V (vs. Ag/AgCl). The H2O2 reduction current is linear to its concentration in the range from 1×10?9 to 2×10?3 M, and the detection limit was found to be 2×10?10 M (S/N=3). The as‐prepared nonenzymatic H2O2 sensor exhibits excellent repeatability, selectivity and long‐term stability.  相似文献   

17.
The present work is about the preparation of silver (Ag)-doped manganese oxide (MnO2)/graphene oxide (GO) composite thin films are deposited by a facile and binder-free successive ionic layer adsorption and reaction (SILAR) method for the first time. The Brunauer-Emmett-Teller (BET) study revealed the nanosheets of MnO2–Ag3/GO exhibit high specific surface area of 192 m2 g?1. The tailored flower-like morphology and interconnected nanosheets of MnO2–Ag3/GO electrodes achieved high electrochemical performance. The maximum specific capacitance (Cs) of 877 F g?1 at the scan rate of 5 mV s?1 is obtained for MnO2–Ag3/GO electrode tested in 1 M sodium sulfate (Na2SO4) electrolyte with capacity retention of 94.57% after 5000 cycling stability. The MnO2–Ag3/GO composite-based flexible solid state symmetric supercapacitor (FSS-SSC) device delivered Cs as 164 F g?1 with specific energy of 57 Wh kg?1 at specific power of 1.6 kW kg?1 and capacitive retention of 94% after 10,000 cycles.  相似文献   

18.
《Electroanalysis》2017,29(11):2507-2515
In the present study, a novel enzymatic glucose biosensor using glucose oxidase (GOx) immobilized into (3‐aminopropyl) triethoxysilane (APTES) functionalized reduced graphene oxide (rGO‐APTES) and hydrogen peroxide sensor based on rGO‐APTES modified glassy carbon (GC) electrode were fabricated. Nafion (Nf) was used as a protective membrane. For the characterization of the composites, Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffractometer (XRD), and transmission electron microscopy (TEM) were used. The electrochemical properties of the modified electrodes were investigated using electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The resulting Nf/rGO‐APTES/GOx/GC and Nf/rGO‐APTES/GC composites showed good electrocatalytical activity toward glucose and H2O2, respectively. The Nf/rGO‐APTES/GC electrode exhibited a linear range of H2O2 concentration from 0.05 to 15.25 mM with a detection limit (LOD) of 0.017 mM and sensitivity of 124.87 μA mM−1 cm−2. The Nf/rGO‐APTES/GOx/GC electrode showed a linear range of glucose from 0.02 to 4.340 mM with a LOD of 9 μM and sensitivity of 75.26 μA mM−1 cm−2. Also, the sensor and biosensor had notable selectivity, repeatability, reproducibility, and storage stability.  相似文献   

19.
《Electroanalysis》2017,29(9):2083-2089
A facile and green electrochemical method for the fabrication of three‐dimensional porous nitrogen‐doped graphene (3DNG) modified electrode was reported. This method embraces two consecutive steps: First, 3D graphene/polypyrrole (ERGO/PPy) composite was prepared by electrochemical co‐deposition of graphene and polypyrrole on a gold foil. Subsequently, the ERGO/PPy composite modified gold electrode was annealed at high temperature. Thus 3DNG modified electrode was obtained. Scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to characterize the structure and morphology of the electrode. The electrode exhibits excellent electroanalytical performance for the reduction of hydrogen peroxide (H2O2). By linear sweep voltammetric measurement, the cathodic peak current was linearly proportional to H2O2 concentration in the range from 0.6 μM to 2.1 mM with a sensitivity of 1.0 μA μM−1 cm−2. The detection limit was ascertained to be 0.3 μM. The anti‐interference ability, reproducibility and stability of the electrode were carried out and the electrode was applied to the detection of H2O2 in serum sample with recoveries from 98.4 % to 103.2 %.  相似文献   

20.
At present, a highly sensitive hydrogen peroxide (H2O2) sensor is fabricated by ferrocene based naphthaquinone derivatives as 2,3‐Diferrocenyl‐1,4‐naphthoquinone and 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone. These ferrocene based naphthaquinone derivatives are characterized by H‐NMR and C‐NMR. The electrochemical properties of these ferrocene based naphthaquinone are investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) on modified glassy carbon electrode (GCE). The modified electrode with ferrocene based naphthaquinone derivatives exhibits an improved voltammetric response to the H2O2 redox reaction. 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone show excellent non‐enzymatic sensing ability towards H2O2 response with a detection limitation of 2.7 μmol/L a wide detection range from 10 μM to 400 μM in H2O2 detection. The sensor also exhibits short response time (1 s) and good sensitivity of 71.4 μA mM?1 cm?2 and stability. Furthermore, the DPV method exhibited very high sensitivity (18999 μA mM?1 cm?2) and low detection limit (0.66 μM) compared to the CA method. Ferrocene based naphthaquinone derivative based sensors have a lower cost and high stability. Thus, this novel non‐enzyme sensor has potential application in H2O2 detection.  相似文献   

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