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1.
In this study, the first application of a capillary zone electrophoresis‐electrochemical detection (CE‐ECD) method for concurrent determination of hydrogen peroxide (H 2O 2) and ascorbic acid (AA), was developed using the Pt nanoparticles (PtNPs) modified Pt micro‐disk electrode (PtME). The electrocatalytic activity of the modified electrode for H 2O 2 and AA was characterized by cyclic voltammetry. Under optimized experimental conditions, highly linear calibration plots were observed for both H 2O 2 and AA, with concentration linear ranges of 0.8 μM to 0.8 mM and 1.0 μM to 0.8 mM. Detection limits of 0.2 μM H 2O 2 and 0.5 μM AA were determined on the basis of the signal‐to‐noise characteristics (S/N=3) of an electropherogram. Compared with the unmodified PtME, the sensitivity was promoted in that PtNPs/PtME provided an increased effective electrode surface and high catalytic activity toward H 2O 2 and AA. Using this method, the added H 2O 2 and AA in Mizone, a kind of functional drink, were detected, and the concentration of AA was found to be 2.33 mM ( n =3). The recovery rates were 95.3 % for H 2O 2 and 98.7 % for AA. The novel approach provided a wide linear range, low detection limit, good reproducibility and stability. It will provide a new insight into the balance of reactive oxygen species and antioxidant in biological systems. 相似文献
2.
A new kind of gold nanoparticles/self-doped polyaniline nanofibers (Au/SPAN) with grooves has been prepared for the immobilization of horseradish peroxidase (HRP) on the surface of glassy carbon electrode (GCE). The ratio of gold in the composite nanofibers was up to 64%, which could promote the conductivity and biocompatibility of SPAN and increase the immobilized amount of HRP molecules greatly. The electrode exhibits enhanced electrocatalytic activity in the reduction of H 2O 2 in the presence of the mediator hydroquinone (HQ). The effects of concentration of HQ, solution pH and the working potential on the current response of the modified electrode toward H 2O 2 were optimized to obtain the maximal sensitivity. The proposed biosensor exhibited a good linear response in the range from 10 to 2000 μM with a detection limit of 1.6 μM (S/N = 3) under the optimum conditions. The response showed Michaelis–Menten behavior at larger H 2O 2 concentrations, and the apparent Michaelis–Menten constant K m was estimated to be 2.21 mM. The detection of H 2O 2 concentration in real sample showed acceptable accuracy with the traditional potassium permanganate titration. 相似文献
3.
A nanocomposite (Ho 2O 3NPs/BNT) was synthesized by decorating holmium(III)oxide nanoparticles (H 2O 3NPs) on bentonite (BNT) through a realizable sonochemical approach for the electrochemical detection of haloperidol (Hlp). A glassy carbon electrode was modified with this nanocomposite. The Ho 2O 3NPs/BNT modified electrode outperformed bare and other modified electrodes in terms of electrochemical performance for Hlp detection in a pH 8.0 phosphate buffer. The proposed electrochemical platform showed a wide linear range (0.01 μM–24 μM), low detection limit (2.4 nM), and high sensitivity by square wave voltammetry. In addition, the proposed electrochemical sensor met the clinical criteria in terms of stability, selectivity, and repeatability. 相似文献
4.
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 (H 2O 2). By linear sweep voltammetric measurement, the cathodic peak current was linearly proportional to H 2O 2 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 H 2O 2 in serum sample with recoveries from 98.4 % to 103.2 %. 相似文献
5.
A novel strategy to fabricate hydrogen peroxide (H 2O 2) sensor was developed by electrodepositing palladium? silver nanoparticles (NPs) on a glassy carbon electrode. The morphology of the modified electrode was characterized by Scanning electron microscopy (SEM). The result of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability, high sensitivity, excellent selectivity towards reduction of hydrogen peroxide (H 2O 2). The response to H 2O 2 is linear in the range between 0.30 μM to 2.50 mM, and the detection limit is 0.1 μM (at an S/N of 3). 相似文献
6.
A sensitive and selective amperometric H 2O 2 biosensor was obtained by utilizing the electrodeposition of Pt flowers on iron oxide‐reduced graphene oxide (Fe 3O 4/rGO) nanocomposite modified glassy carbon electrode (GCE). The morphology of Fe 3O 4/rGO and Pt/Fe 3O 4/rGO was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The step‐wise modification and the electrochemical characteristics of the resulting biosensor were characterized by cyclic voltammetry (CV) and chronoamperometry methods. Thanks to the fast electron transfer at the Pt/Fe 3O 4/rGO electrode interface, the developed biosensor exhibits a fast and linear amperometric response upon H 2O 2. The linear range of Pt/Fe 3O 4/rGO is 0.1∼2.4 mM (R 2=0.998), with a sensitivity of 6.875 μA/mM and a detection limit of 1.58 μM (S/N=3). In addition, the prepared biosensor also provides good anti‐interferent ability and long‐term stability due to the favorable biocompatibility of the electrode interface. The proposed sensor will become a reliable and effective tool for monitoring and sensing the H 2O 2 in complicate environment. 相似文献
7.
At present, a highly sensitive hydrogen peroxide (H 2O 2) 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 H 2O 2 redox reaction. 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone show excellent non‐enzymatic sensing ability towards H 2O 2 response with a detection limitation of 2.7 μmol/L a wide detection range from 10 μM to 400 μM in H 2O 2 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 H 2O 2 detection. 相似文献
8.
An acetylcholinesterase (AChE) purified from maize seedlings was immobilized covalently onto iron oxide nanoparticles (Fe 3O 4NP) and carboxylated multi walled carbon nanotubes (c-MWCNT) modified Au electrode. An organophosphorus (OP) biosensor was fabricated using this AChE/Fe 3O 4/c-MWCNT/Au electrode as a working electrode, Ag/AgCl as standard and Pt wire as an auxiliary electrode connected through a potentiostat. The biosensor was based on inhibition of AChE by OP compounds/insecticides. The properties of nanoparticles modified electrodes were studied by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS). The synergistic action of Fe 3O 4NP and c-MWCNT showed excellent electrocatalytic activity at low potential (+0.4 V). The optimum working conditions for the sensor were pH 7.5, 35 °C, 600 μM substrate concentration and 10 min for inhibition by pesticide. Under optimum conditions, the inhibition rates of OP pesticides were proportional to their concentrations in the range of 0.1–40 nM, 0.1–50 nM, 1–50 nM and 10–100 nM for malathion, chlorpyrifos, monocrotophos and endosulfan respectively. The detection limits were 0.1 nM for malathion and chlorpyrifos, 1 nM for monocrotophos and 10 nM for endosulfan. The biosensor exhibited good sensitivity (0.475 mA μM −1), reusability (more than 50 times) and stability (2 months). The sensor was suitable for trace detection of OP pesticide residues in milk and water. 相似文献
9.
Poly(toluidine blue) nanowires (PTBNWs) with an average diameter of ca. 200 nm and length of ca. 5 μm were synthesized for the first time using a template‐directed electropolymerization strategy with a nanopore polycarbonate (PC) membrane template. Their morphological characterization was carried out by scanning electron microscopy (SEM) and transmission electron microscope (TEM). By electrochemical polymerization, horseradish peroxidase (HRP) was encapsulated in situ in PTBNWs (denoted as PTBNWs‐HRP) for potential biosensor applications. PTBNWs‐HRP was then modified on a glassy carbon (GC) electrode. In the system obtained, the PTBNWs served as an excellent redox mediator and exhibited high efficiency of electron transfer between the HRP and the GC electrode for the reduction of H 2O 2. The proposed electrode can be used as an excellent amperometric sensor for H 2O 2 at ?0.1 V with a linear response range covering from 1 μM to 28 mM, a detection limit of 1 μM (based on S/N=3) and a fast response time of less than 8 s. 相似文献
10.
Some nanostructures are reported to possess enzyme-mimetic activities similar to those of natural enzymes. Herein, highly-dispersed Pt nanodots on Au nanorods (HD- PtNDs@AuNRs) with mimetic peroxidase activity were designed as an active electrode modifier for fabrication of a hydrogen peroxide (H 2O 2) electrochemical sensor. The HD-PtNDs@AuNRs were synthesized by a seed-mediated growth approach and confirmed by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and UV–vis spectroscopy. The electrochemical and catalytical performances of HD-PtNDs@AuNRs towards H 2O 2 reduction were investigated in detail by cyclic voltammetry and amperometry. The HD-PtNDs@AuNRs modified electrode displayed a high catalytic activity to H 2O 2 at −0.10 V (versus SCE), a rapid response within 5 s, a wide linear range of 2.0–3800.0 μM, a detection limit of 1.2 μM (S/N = 3), and a high sensitivity of 181 μA mM −1 cm −2. These results suggested a promising potential of fabricating H 2O 2 electrochemical sensor using HD- PtNDs@AuNRs. 相似文献
11.
A Pt nanoparticle modified Pencil Graphite Electrode (PGE) was proposed for the electrocatalytic oxidation and non‐enzymatic determination of H 2O 2 in Flow Injection Analysis (FIA) system. Platinum nanoparticles (PtNPs) electrochemically deposited on pretreated PGE (p.PGE) surface by recording cyclic voltammograms of 1.0 mM of H 2PtCl 6 solution in 0.10 M KCl at scan rate of 50 mV s −1 for 30 cycles. Cyclic voltammograms show that the oxidation peak potential of H 2O 2 shifts from about +700 mV at bare PGE to +50 mV at PtNPs/p.PGE vs. Ag/AgCl /KCl (sat.). It can be concluded that PtNPs/p.PGE exhibits a good electrocatalytic activity towards oxidation of H 2O 2. Then, FI amperometric analysis of H 2O 2 was performed under optimized conditions using a new homemade electrochemical flow cell which was constructed for PGE. Linear range was found as 2.5 μM to 750.0 μM H 2O 2 with a detection limit of 0.73 μM (based on S b/m of 3). As a result, this study shows the first study on the FI amperometric determination of H 2O 2 at PtNPs/p.PGE which exhibits a simple, low cost, commercially available, disposable sensor for H 2O 2 detection. The proposed electrode was successfully applied to determination of H 2O 2 in real sample. 相似文献
12.
A new convenient strategy to fabricate a third‐generation hydrogen peroxide biosensor was described. The screen‐printed carbon electrode (SPCE) was first modified with a layer of 4‐nitrophenyl assembled from the 4‐nitroaniline diazonium salt synthesized in situ in acidic aqueous solution. Next, the nitro groups were converted to amines followed by crosslinking to the horseradish peroxidase (HRP) by glutaraldehyde. The redox chemistry of the active center of the HRP was observed and the HRP‐modified electrode displayed electrocatalytic activity towards the reduction of hydrogen peroxide (H 2O 2) without any mediators. H 2O 2 was determined in a linear range from 5.0 μM to 50.0 μM, with a detection limit of 1.0 μM. Furthermore, the biosensor exhibited fast amperometric response, good reproducibility and long‐term stability. 相似文献
13.
A platinum (Pt) film coated n-silicon (Pt/n-n +-Si) was modified with nickel(II)-potassium hexacyanoferrate (NiHCF)-graphene sheets (GS) hybrid and used as a photo-electrochemical (PEC) sensor for non-enzyme hydrogen peroxide (H 2O 2) detection. A NiHCF film was deposited on the surface of GS/Pt/n-n +-Si electrode by chemical method. The structure and composition of the NiHCF film was characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). PEC behavior of the NiHCF-GS/Pt/n-n +-Si electrode was investigated using cyclic voltammetry (CV) under illumination. The modified electrode has been used as PEC sensor for H 2O 2 detection with a linear range of 2.0 × 10 ?6–2.9 × 10 ?3 M and a detection limit of 1.0 × 10 ?6 M at a signal-to-noise ratio of 3 in a two-electrode cell with a Pt plate as counter electrode. The characteristics of GS layer have been discussed in both the improvement of sensibility and selectivity. 相似文献
14.
In this study, Prussian blue (PB) film on the electroreduced graphene oxide (ERGO)‐modified Au electrode surface (ERGO/PB) is easily prepared by means of cyclic voltammetric technique in the mixture of K 3Fe(CN) 6 and FeCl 3. Its electrochemical behaviors for NADH biosensor are studied. The structural and morphological characters of modified electrode material are analyzed with using of XPS, XRD, Raman, EDS, and SEM techniques. ERGO/PB hybrid nanocomposite for NADH biosensor is exhibited to the higher catalytic effect (linear range from 1.0 to 100 μM, detection limit of 0.23 μM at S/N=3) compared to naked Au, ERGO‐modified Au, and PB‐modified Au electrodes. In addition to, ERGO/PB electrode was used to voltammetric and amperometric detection of H 2O 2. ERGO/PB electrodes also showed the same behavior as the NADH sensor. This ERGO/PB‐modified electrode supplied a simple, new, and low‐cost route for amperometric sensing of both NADH and H 2O 2. 相似文献
15.
A novel hemin/phytic acid doped polyaniline (PA-PANI) hydrogel composite was prepared through a simple chemical and self-assembly method, which was modified onto electrode for electrochemical detection of H 2O 2 released from living cells. It showed good analytical performance with high sensitivity, selectivity and a rapid response for the analysis of H 2O 2 in the range of 2 to 102 μM, with the detection limit of 1.2 μM. The favorable results mainly originated from both the high conductivity of PA-PANI hydrogel and its network structure preventing hemin from self-dimerization to provide active catalytic species. Furthermore, PA-PANI with good biocompatibility allowed living cells to adhere and resulted in a short diffusion distance between H 2O 2 released from cells and electrode. 相似文献
16.
We report a simple approach to the production of carbon fiber‐based amperometric microbiosensors for selective detection of hydrogen peroxide (H 2O 2), which was achieved by electrometallization of carbon fiber microelectrodes (CFMs) by electrodeposition of Pt nanoparticles. The Pt‐carbon hybrid sensing interface provided a sensitivity of 7711±587 μA ? mM ?1 ? cm ?2, a detection limit of 0.53±0.16 μM (S/N=3), a linear range of 0.8 μM–8.6 mM, and a response time of <2 sec. The morphologies of the Pt nanoparticle‐modified CFMs were characterized by scanning electron microscopy. To achieve selectivity, permseletive layers, polyphenylenediamine (PPD) and Nafion, were deposited resulting in exclusion of the anionic and cationic interferents, ascorbic acid and dopamine, respectively, at their physiologically relevant concentrations. The resultant sensors displayed a sensitivity to hydrogen peroxide of 1381±72 μA ? mM ?1 ? cm ?2, and a detection limit of 0.86±0.19 μM (S/N=3). This simple and rapid metallization method converts carbon fiber microelectrodes, which are readily accessible, to microscale Pt electrodes in 2 min, providing a platform for oxidase‐based amperometric biosensors with improved spatial resolution over more commonly used platinum electrode array microprobes. 相似文献
17.
A bioelectrochemical platform has been constructed for the direct electron transfer and biosensing purposes of microperoxidase‐11 (MP‐11) immobilized on the chitosan dispersed multilayer graphene nanocomposite. The immobilized MP‐11 at the modified gold electrode displays a well‐defined and quasireversible redox peaks, with a formal potential of ?0.38 V/SCE in a buffer solution (pH 7.0). MP‐11 absorbed on the electrode surface exhibits high electrocatalytic activity toward the reduction of both oxygen and hydrogen peroxide and also shows good analytical performance for the amperometric detection of H 2O 2 with a linear range from 2.5 to 135 μM. These results indicate the graphene modified electrode might be used as a third generation biosensor for H 2O 2 detection. 相似文献
18.
Developing non‐noble‐metal electrocatalyst for non‐enzymatic H 2O 2 sensing is highly attractive. A facile, two‐step approach has been utilized for the synthesis of PBNCs/SnO 2 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 H 2O 2 using the Amperometry technique. Under optimum conditions, PBNCs/SnO 2 QDs/RGO ternary nanocomposite performed very well in the electrocatalytic reduction of H 2O 2 with a linear dynamic range from 25–225 μM (R 2=0.996) with a low detection limit of 71 nM (S/N=3). Compared to the recent literature, PBNCs/SnO 2QDs/RGO ternary nanocomposite based modified electrode exhibit a wider linear dynamic range with a low detection limit. Furthermore, PBNCs/SnO 2 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 H 2O 2 in tap water with acceptable recovery. The present performance of PBNCs/SnO 2 QDs/RGO ternary nanocomposite material towards H 2O 2 sensing might widen its application for developing a new type of non‐noble metal‐based non‐enzymatic electrochemical biosensors. 相似文献
19.
Magnetic carbon-coated iron nanoparticles were used to immobilize horseradish peroxidase on the surface of a polythionine modified glassy carbon electrode in combination with chitosan and cross-linking of glutaraldehyde. The electrochemical character of this enzyme electrode and its electrocatalytic reduction to H2O2 were studied by cyclic voltammetry. The effects of the common experimental variables were investigated. Under the optimum conditions, this method could be successfully used for the amperometric determination of H2O2 in a wide concentration range of 9.6 μM to 3.16 mM with a detection limit of 3.6 μM (S/N=3). Besides, the biosensor also exhibited good selectivity, stability and reproducibility. 相似文献
20.
MWCNTs‐nanoNiO composite was used as a glassy carbon electrode modifier for construction of a novel catalase nanobiosensor for hydrogen peroxide. The immobilized catalase exhibited excellent electrocatalytic activity towards the reduction of H 2O 2. The resulting amperometric biosensor exhibited a linear response over a concentration range of 200 µM to 2.53 mM with a low detection limit of 19.0 µM. Electrochemical impedance measurements revealed that the modified electrode can be used for the sensitive detection of H 2O 2. The charge transfer resistance found to decrease significantly after enzymatic reaction of nanobiosensor with H 2O 2. The resulting impedance was highly sensitive to H 2O 2 over a linear range of 19–170 nM with a detection limit of 2.4 nM. 相似文献
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