首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
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.
Fullerence C60‐cryptand 22 was prepared and successfully applied as the electric carrier in the PVC electrode membrane of a bifunctional ion‐selective electrode for cations, e.g., Ag+ ions as well as anions, e.g., I? ions. The bifunctional ion‐selective electrode based on C60‐cryptand 22 can be applied as a Silver (Ag+) ion selective electrode with an internal electrode solution of 10?3 M AgNO3 in water (pH = 6.3), or as an Iodide (I?) ion selective electrode with an acidic internal electrode solution of 10?4 M KI(aq) (pH = 2) in which the cryptand 22 is protonated, and the C60‐cryptand 22 is changed to C60‐Cryptand22–H+ and becomes an anionic electro‐carrier to absorb the I? ion. The Ag+ ion selective electrode based on C60‐cryptand 22 gave a linear response with a near‐Nernstian slope (59.5 mV decade?1) within the concentration range 10?1‐10?3 M Ag+(aq). The Ag+ ion electrode exhibited comparatively good selectivity for silver ions, over other transition‐metal ions, alkali and alkaline earth metal ions. The Ag+ ion selective electrode with good stability and reproducibility was successfully used for the titration of Ag+(aq) with Cl? ions. The Iodide (I?) Ion selective electrode based on protonated C60–cryptand22‐H+ also showed a linear response with a nearly Nernstian slope (58.5 mV decade?1) within 10?1 ‐ 10?3 M I? (aq) and exhibited good selectivity for I? ions and had small selectivity coefficients (10?2–10?3) for most of other anions, e.g., F? , OH?, CH3COO?, SO42?, CO32?, CrO42?, Cr2O72? and PO43? ions.  相似文献   

3.
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   

4.
A hemoglobin‐titanate composite based biosensor was chosen for determination of H2O2 in an acidic medium. CV results of the Hb‐titanate modified pyrolytic graphite electrode showed a pair of well‐defined, quasi‐reversible redox peaks centered at ?246 mV (vs. Ag/AgCl) in a pH 5.0 HAc‐NaAc buffer solution. The modified electrode exhibited good electrocatalytic response for monitoring H2O2 and had a large linear detection range from 20 μM to 3.2 mM with a detection limit of 8 μM (S/N=3) and a sensitivity of 29.7 mA M?1 cm?2 in the pH 5.0 solution. The biosensor also possessed good long term storage stability.  相似文献   

5.
《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   

6.
We developed a novel iron‐tetrasulfophthalocyanine‐graphene‐Nafion (FeTSPc‐GR‐Nafion) modified screen‐printed electrode to determine hydrogen peroxide (H2O2) with high sensitivity and selectivity. The nanocomposite film (FeTSPc‐GR‐Nafion) exhibits an excellent electrocatalytic activity towards oxidation of H2O2 at a potential of +0.35 V in the absence of enzyme. A comparative study reveals that the FeTSPc‐GR complexes play a dual amplification role. Amperometric experiment indicates that the sensors possess good sensitivity and selectivity, with a linear range from 2.0×10?7 M to 5.0×10?3 M and a detection limit of 8.0×10?8 M. This sensor has been successfully used to develop the glucose biosensor and has also been applied to determine H2O2 in sterile water.  相似文献   

7.
Ag/MnO2/GO nanocomposites were synthesized via the method of gas/liquid interface based on silver mirror reaction, and a non‐enzymatic H2O2 sensor was fabricated through immobilizing Ag/MnO2/GO nanocomposites on GCE. The composition and morphology of the nanocomposites were studied by energy‐dispersive X‐ray spectroscopy (EDS), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Electrochemical investigation indicated that it exhibited a favorable performance for the H2O2 detection. Its linear detection range was from 3 μM to 7 mM with a correlation coefficient of 0.9960; the sensitivity was 105.40 μA mM?1 cm?2 and the detection limit was estimated to be 0.7 μM at a signal‐to‐noise ratio of 3.  相似文献   

8.
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   

9.
Mesoporous silica thin films encapsulating a molecular iron‐triazole complex, Fe(Htrz)3 (Htrz=1,2,4,‐1H‐triazole), have been generated by electrochemically assisted self‐assembly (EASA) on indium‐tin oxide (ITO) electrode. The obtained modified electrodes are characterized by well‐defined voltammetric signals corresponding to the FeII/III centers of the Fe(Htrz)3 species immobilized into the films, indicating fast electron transfer processes and stable operational stability. This is due to the presence of a high density of redox probes in the material (1.6×10?4 mol g?1 Fe(Htrz)3 in the mesoporous silica film) enabling efficient charge transport by electron hopping. The mesoporous films are uniformly deposited over the whole electrode surface and they are characterized by a thickness of 110 nm and a wormlike mesostructure directed by the template role played by Fe(Htrz)3 species in the EASA process. These species are durably immobilized in the material (they are not removed by solvent extraction). The composite mesoporous material (denoted Fe(Htrz)3@SiO2) is then used for the electrocatalytic detection of hydrogen peroxide, which can be performed by amperometry at an applied potential of ?0.4 V versus Ag/AgCl and by flow injection analysis. The organic‐inorganic hybrid film electrode displays good sensitivity for H2O2 sensing over a dynamic range from 5 to 300 μM, with a detection limit estimated at 2 μM.  相似文献   

10.
Developing non‐noble‐metal electrocatalyst for non‐enzymatic H2O2 sensing is highly attractive. A facile, two‐step approach has been utilized for the synthesis of PBNCs/SnO2 QDs/RGO ternary nanocomposite. TEM, SEM, XPS, and XRD techniques were used to the characterize the structural and morphological properties of synthesized ternary nanocomposite. The synthesized ternary nanocomposite has been examined as an electrode material for the electrochemical detection of H2O2 using the Amperometry technique. Under optimum conditions, PBNCs/SnO2 QDs/RGO ternary nanocomposite performed very well in the electrocatalytic reduction of H2O2 with a linear dynamic range from 25–225 μM (R2=0.996) with a low detection limit of 71 nM (S/N=3). Compared to the recent literature, PBNCs/SnO2QDs/RGO ternary nanocomposite based modified electrode exhibit a wider linear dynamic range with a low detection limit. Furthermore, PBNCs/SnO2 QDs/RGO ternary nanocomposite based modified electrode showed an excellent anti‐interference ability against various common interfering agents. The practical applicability of this ternary nanocomposite based modified electrode was further extended to determine the H2O2 in tap water with acceptable recovery. The present performance of PBNCs/SnO2 QDs/RGO ternary nanocomposite material towards H2O2 sensing might widen its application for developing a new type of non‐noble metal‐based non‐enzymatic electrochemical biosensors.  相似文献   

11.
In this study, a laser‐induced graphene (LIG) loaded platinum nanoparticles (PtNPs) was prepared for precise, rapid and non‐enzymatic electrochemical detection of hydrogen peroxide (H2O2). The commercial PI films were used as the substrate of LIG. In order to improve the electrochemical performance of LIG, a layer of PtNPs catalyst was fabricated through a magnetron sputtering process on the surface of LIG (PtLIG). Under optimized conditions, a linear relationship between H2O2 reduction current and H2O2 concentration was recorded, the correlation coefficient R2 is 0.9919 with the detection limit of 0.1 μM (S/N=3) and the sensitivity of 248.4 μA mM?1cm?2. Moreover, the PtLIG exhibits excellent selectivity, reproducibility and repeatability. Because of these remarkable advantages, we believe that PtLIG will provide a wider range of applications in biosensors and bioelectronic devices.  相似文献   

12.
《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   

13.
Horseradish peroxidase, previously modified with 1‐adamantane moieties, was supramolecularly immobilized on gold electrodes coated with perthiolated β‐cyclodextrin. The functionalized electrode was employed for the construction of an amperometric biosensor device for hydrogen peroxide using 1 mM hydroquinone as electrochemical mediator. The biosensor exhibited a fast amperometric response (6 s) and a good linear response toward H2O2 concentration between 12 μM and 450 μM. The biosensor showed a sensitivity of 1.02 mA/M cm2, and a very low detection limit of 5 μM. The electrode retained 97% of its initial electrocatalytic activity after 30 days of storage at 4 0C in 50 mM sodium phosphate buffer, pH 7.0.  相似文献   

14.
《Electroanalysis》2005,17(22):2068-2073
A new cathodic scheme for hydrogen peroxide (H2O2) measurement by Fe3O4‐based chemical sensor was described. The unique characteristic of electrocatalytic property was firstly investigated by voltammetry. And then the amperometric response of H2O2 was measured at ?0.2 V (vs. Ag/AgCl) by Fe3O4 modified glassy carbon rotating disk electrode. The kinetic parameter was also calculated from Koutecky‐Levich plot, and the value was 6.4×10?4 cm s?1 in pH 3 citrate buffer. In order to benefit the possible biomedical applications, Fe3O4/chitosan modified electrode was also investigated in this experiment. There were several characteristic enhancements by the coated chitosan thin film for H2O2 sensor. The calibration curves were found to be linear up to 4.0 and 5.0 mM (r=0.999) in pH 3 and 7 with the detection limits of 7.6 and 7.4 μM L?1 (S/N=3). The stability was evaluated by the results of half‐life time (t50%) for 9 months at room temperature and 24 months at 4 °C.  相似文献   

15.
《Electroanalysis》2017,29(5):1443-1450
In this study, inorganic/organic composites containing poly (N‐isopropylacrylamide) coated core‐shell SiO2 microspheres were prepared via surface‐initiated atom transfer radical polymerization (ATRP). The thermal responsive polymer, N‐isopropylacrylamide was treated with methanol, water and CuBr/CuBr2/1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) at room temperature to form PNIPAM@SiO2 microspheres. The as‐prepared PNIPAM@SiO2 microspheres were characterized by FT‐IR, TGA, XPS, SEM, TEM analyses. Hemoglobin (Hb) was immobilized onto the surfaces of PNIPAM@SiO2 microspheres via hydrophobic and π‐π stacking interactions. The as‐prepared Hb/PNIPAM@SiO2 electrode exhibits well‐defined redox peak at a formal potential of −0.38 V, validating the direct electrochemistry of Hb. The Hb immobilized composite film retained its bioelectroactivity without any significant loss of catalytic activity. The modified electrode detects H2O2 over a wide linear concentration range (0.1 μM to 333 μM) with a detection limit of 0.07 μM. This modified electrode also successfully detects H2O2 from food and disinfectant samples with appreciable recovery values, validating its practicality. We believe that PNIPAM@SiO2 composite has great potential to be used in the detection of H2O2 and development of other enzyme based biosensors.  相似文献   

16.
In this work, a novel sensor for detecting hydrogen peroxide was constructed on the base of nanotubular TiO2 and platinum nanoparticles. The morphology, structural, and electrochemical properties of the Pt/TiO2 nanocomposite electrodes were characterized by SEM, XRD and electrochemical methods. With an operating potential of +0.3 V versus Ag/AgCl, the sensor produces catalytic oxidation currents at the nanocomposite electrode, which can be exploited for quantitative determinations. The amperometric signals are linearly proportional to hydrogen peroxide concentration in the range 4×10?6 to 1.25×10?3 M. The regression equation is I (μA)=0.85 c (mM)+0.16 with a correction coefficient of 0.997. At a signal‐to‐noise ratio of 3, a detection limit of 4.0 μM H2O2 can be observed for the nanocomposite electrode. In addition, the sensor has a good stability and reproducibility. The construction process is simple and inexpensive. The results demonstrated that nanotubular TiO2 exhibits great prospect for developing a class of ideal and novel bioreactors and biosensors.  相似文献   

17.
《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   

18.
The present work describes reduction of iodate (IO3?), and periodate (IO4?) at silicomolybdate‐doped‐glutaraldehyde‐cross‐linked poly‐L ‐lysine (PLL‐GA‐SiMo) film coated glassy carbon electrode in 0.1 M H2SO4. In our previous study, we were able to prepare the PLL‐GA‐SiMo film modified electrode by means of electrostatically trapping SiMo12O404? mediator in the cationic film of PLL‐GA, and the voltammetric investigation in pure supporting indicated that the charge transport through the film was fast. Here, the electrocatalytic activity of PLL‐GA‐SiMo film electrode towards iodate and periodate was tested and subsequently used for analytical determination of these analytes by amperometry. The two electron reduced species of SiMo12O404? anion was responsible for the electrocatalytic reduction of IO3? at PLL‐GA‐SiMo film electrode while two and six electron reduced species were showed electrocatalytic activity towards IO4? reduction. Under optimized experimental conditions of amperometry, the linear concentration range and sensitivity are 2.5×10?6 to 1.1×10?2 M and 18.47 μA mM?1 for iodate, and 5×10?6 to 1.43×10?4 M and 1014.7 μA mM?1 for periodate, respectively.  相似文献   

19.
《Electroanalysis》2006,18(3):259-266
In this paper, a new strategy for constructing a mediator‐type amperometric hydrogen peroxide (H2O2) microbiosensor was described. An electropolymerized thionine film (PTH) was deposited directly onto a gold electrode surface. The resulting redox film was extremely thin, adhered well onto a substrate (electrode), and had a highly cross‐linked network structure. Consequently, horseradish peroxidase (HRP) was successfully immobilized on nanometer‐sized Au colloids, which were supported by thiol‐tailed groups of 11‐mercaptoundecanoic acid (11‐MUA) monolayer covalently bound onto PTH film. With the aid of the PTH mediator, HRP‐labeled Au colloids microbiosensor displayed excellent electrocatalytical response to the reduction of H2O2. This matrix showed a biocompatible microenvironment for retaining the native activity of the covalent HRP and a very low mass transport barrier to the substrate, which provided a fast amperometric response to H2O2. The proposed H2O2 microbiosensor exhibited linear range of 3.5 μM–0.7 mM with a detection limit of 0.05 μM (S/N=3). The response showed a Michaelis‐Menten behavior at larger H2O2 concentrations. The KMapp value for the biosensors based on 24 nm Au colloids was found to be 47 μM, which demonstrated that HRP immobilized on Au colloids exhibited a high affinity to H2O2 with no loss of enzymatic activity. This microbiosensor possessed good analytical performance and storage stability.  相似文献   

20.
In this paper, self‐assembled Prussian blue nanoparticles (PBNPs) on carbon ceramic electrode (CCE) were developed as a high sensitive hydrogen peroxide (H2O2) electrochemical sensor. The PBNPs film was prepared by a simple dipping method. The morphology of the PBNPs‐modified CCE was characterized by scanning electron microscopy (SEM). The self‐assembled PB film exhibited sufficient mechanical, electrochemical stability and high sensitivity in compare with other PB based H2O2 sensors. The sensor showed a good linear response for H2O2 over the concentration range 1 μM–0.26 mM with a detection limit of ca. 0.7 μM (S/N=3), and sensitivity of 754.6 mA M?1 cm?2. This work demonstrates the feasibility of self‐assembled PBNPs‐modified CCE for practical sensing applications.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号