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1.
A novel biocomposite film based on hyaluronic acid (HA) and hydrophilic room temperature ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([EMIM][BF4]) was explored. Here, HA was used as a binder to form [EMIM][BF4]-HA composite film and help [EMIM][BF4] to attaching on glass carbon electrode (GCE) surface, while doping [EMIM][BF4] in HA can effectively reduce the electron transfer resistance of HA. The composite film can be readily used as an immobilization matrix to entrap myoglobin (Mb). A pair of well-defined and quasi-reversible redox peaks of Mb was obtained at the Mb-[EMIM][BF4]-HA composite film modified GCE (Mb-[EMIM][BF4]-HA/GCE) through direct electron transfer between Mb and the underlying electrode. The Mb-[EMIM][BF4]-HA/GCE showed an excellent electrocatalytic activity toward the reduction of H2O2. Based on the [EMIM][BF4]-HA biocomposite film, a third-generation reagentless biosensor could be constructed for the determination of H2O2. 相似文献
2.
《Electrochemistry communications》2007,9(9):2202-2206
Cytochrome c (Cyt c) and a room temperature ionic liquid (RTIL), 2-methyl-N-butylpyridinium tetrafluoroborate ([2-MBPy][BF4]), were immobilized on the surface of a basal plane graphite (BPG) electrode. Direct electron transfer from Cyt c to BPG electrode was clearly observed. A pair of well-defined and reversible redox peaks could be obtained in a 0.13 M [2-MBPy][BF4] aqueous solution. The anodic and cathodic peak potentials of Cyt c were at −0.064 and −0.020 V (vs. Ag/AgCl), respectively. The results showed that [2-MBPy][BF4] promoted the direct electron transfer between Cyt c and the BPG electrode. Cyt c immobilized on BPGE can catalyze the reduction of hydrogen peroxide. Based on this, a biosensor can be constructed to detect quantitatively hydrogen peroxide. 相似文献
3.
《Electrochemistry communications》2007,9(5):920-924
A room temperature ionic liquid (RTIL), 1-ethyl-3-methyl imidazolium tetrafluoroborate ([EMIm][BF4]), was successfully immobilized on the surface of a basal plane graphite (BPG) electrode through silica sol and Nafion film to form a sol/RTIL/Nafion modified electrode. Direct electrochemistry of hemoglobin (Hb), which was adsorbed on the surface of sol/RTIL/Nafion modified electrode, was investigated. The results from cyclic voltammetry (CV) suggested that Hb could be tightly adsorbed on the surface of the electrode. A couple of well-defined and quasi-reversible CV peaks of Hb can be observed in a phosphate buffer solution (pH 7.0). RTIL shows an obvious promotion for the direct electro-transfer between Hb and electrode. Hb adsorbed on electrode surface exhibits an obvious electrocatalytic activity for the reduction of oxygen O2. The reduction peak currents were proportional linearly to the concentration of oxygen in the range 0.14–1.82 μM. A third generation biosensor based on RTIL can be constructed for the determination of O2. 相似文献
4.
《Electrochemistry communications》2007,9(7):1648-1654
Stable heme proteins entrapped in dimethylformamide (DMF)–chitosan organohydrogel films modified electrodes were operated in neat hydrophilic room-temperature ionic liquid (IL) [bmim][BF4] for the first time. The modified electrodes possess outstanding electrochemical response in [bmim][BF4] without adding water. The morphology studies of films were demonstrated by atomic force microscopy (AFM). UV–Vis and FTIR spectroscopy showed that the heme proteins retained their native structure in organohydrogel films. Direct electrochemistry and bioelectrocatalysis of heme protein–organohydrogel films were investigated. Several electrochemical parameters such as the charge transfer coefficients (α) and the apparent electron transfer rate constant (ks) of these processes were calculated by performing nonlinear regression analysis of square wave voltammetry (SWV) experimental dates. Furthermore, high electrocatalytic activity to hydrogen peroxide (H2O2) was observed, indicating that heme proteins entrapped in organohydrogel films retained their bioelectrocatalytic activities in [bmim][BF4]. Kinetic analysis of the cyclic voltammetry dates shows that heme protein–organohydrogel films operated in IL bring up to an enhancement of the biosensor sensitivity and a high affinity for H2O2. 相似文献
5.
6.
Yuhuan Chen Suojiang Zhang Xiaoliang Yuan Yanqiang Zhang Xiangping Zhang Ryohei Mori 《Thermochimica Acta》2006,441(1):42-44
The solubility of CO2 in imidazolium ionic liquids (ILs), 1-butyl-3-methyl imidazolium tetrafluoroborate ([bmim][BF4]), 1-hexyl-3-methyl imidazolium tetrafluoroborate ([hmim][BF4]) and 1-octyl-3-methyl imidazolium tetrtafluoroborate ([omim][BF4]) was determined at 305-25 K and pressures from 1 to 9 MPa. The influence of chain length of alkyl substituents on the imidazolium cation on the solubility of CO2 was investigated. The differences in solubility with chain length are in the sequence [omim][BF4] > [hmim][BF4] > [bmim][BF4]. The solubility data were correlated by the extended Henry's law, and enthalpy, Gibbs free energy and entropy changes were obtained. 相似文献
7.
S. Ashok Kumar 《Talanta》2007,72(2):831-838
The adsorption processes and electrochemical behavior of 4-nitroaniline (4-NA) adsorbed onto glassy carbon electrodes (GCE) have been investigated in aqueous 0.1 M nitric acid (HNO3) electrolyte solutions using cyclic voltammetry (CV). 4-NA adsorbs onto GCE surfaces, and upon potential cycling past −0.2 V, is transformed into the arylhydroxylamine (ArHA) derivative which exhibits a well-behaved pH dependent redox couple centered at 0.32 V at pH 1.5. It is noted as arylhydroxylamine modified glassy carbon electrodes (HAGCE). This modified electrode can be readily used as an immobilization matrix to entrap proteins and enzymes. In our studies, myoglobin (Mb) was used as a model protein for investigation. A pair of well-defined reversible redox peaks of Mb (Fe(III)-Fe(II)) was obtained at the Mb/arylhydroxylamine modified glassy carbon electrode (Mb/HAGC) by direct electron transfer between the protein and the GCE. The formal potential (E0′), the apparent coverage (Γ*) and the electron-transfer rate constant (ks) were calculated as −0.317 V, 8.26 × 10−12 mol/cm2 and 51 ± 5 s−1, respectively. Dramatically enhanced biocatalytic activity was exemplified at the Mb/HAGC electrode by the reduction of hydrogen peroxide (H2O2), trichloroacetic acid (TCA) and oxygen (O2). The Mb/arylhydroxylamine film was also characterized by UV-visible spectroscopy (UV-vis), scanning electron microscope (SEM) indicating excellent stability and good biocompatibility of the protein in the arylhydroxylamine modified electrode. This new Mb/HAGC electrode exhibited rapid electrochemical response (2 s) for H2O2 and had good stability in physiological condition, showing the potential applicability of the films in the preparation of third generation biosensors or bioreactors based on direct electrochemistry of the proteins. 相似文献
8.
A new amperometric biosensor for hydrogen peroxide (H2O2) has been developed that is based on direct electrochemistry and electrocatalysis of hemoglobin (Hb) in a multilayer inorganic–organic
hybrid film. o-Phenylenediamine (PDA) was electropolymerized onto a glassy carbon electrode (GCE), and then negatively charged nanogold
particles and positively charged poly(diallyldimethylammonium chloride) (PDDA) were alternately assembled on the PDA/GCE surface.
Finally, Hb was electrostatically adsorbed on the surface of gold nanoparticles. The electrochemical behavior of the resulting
biosensor (Hb/{nanogold/PDDA}n/PDA/GCE) was assessed and optimized. The performance and factors influencing the biosensor were studied in detail. Under
optimal conditions, the immobilized Hb displayed good electrocatalytic response to the H2O2 reduction ranging from 1.3 μM to 1.4 mM with a detection limit of 0.8 μM (at 3δ). In addition, the biosensor exhibited rapid
response, good reproducibility, and long-term stability.
Electronic supplementary material to this paper is available in electronic form at
Correspondence: Dianyong Tang, Department of Chemistry and Life Science, Leshan Teachers College, Sichuan (Leshan) 614000,
P.R. China 相似文献
9.
A facile phospholipid/room‐temperature ionic liquid (RTIL) composite material based on dimyristoylphosphatidylcholine (DMPC) and 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim]PF6) was exploited as a new matrix for immobilizing protein. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were adopted to characterize this composite film. Hemoglobin (Hb) was chosen as a model protein to investigate the composite system. UV‐vis absorbance spectra showed that Hb still maintained its heme crevice integrity in this composite film. By virtue of the Hb/DMPC/[bmim]PF6 composite film‐modified glassy carbon electrode (GCE), a pair of well‐defined redox peaks of Hb was obtained through the direct electron transfer between protein and underlying GCE. Moreover, the reduction of O2 and H2O2 at the Hb/DMPC/[bmim]PF6 composite film‐modified GCE was dramatically enhanced. 相似文献
10.
We have prepared a novel sensor for hydrogen peroxide that is based on a glassy carbon electrode modified with a film containing multi-walled carbon nanotubes wired to CuO nanoflowers. The nanoflowers were characterized by X-ray powder diffraction, and the electrode was characterized by cyclic voltammetry (CV) and scanning electron microscopy. The response of the modified electrode towards hydrogen peroxide was investigated by CV and chronoamperometry and showed it to exhibit high electrocatalytic activity, with a linear range from 0.5?μM to 82?μM and a detection limit of 0.16?μM. The sensor also displays excellent selectivity and stability. Graphical abstract
We have prepared a novel sensor for hydrogen peroxide (H2O2) that is based on a glassy carbon electrode modified with a film containing multi-walled carbon nanotubes (MWCNTs) wired to CuO nanoflowers. The scheme shows the construction of the MWCNTs-wired CuO nanoflowers modified electrode and electrocatalytic activity towards H2O2. When H2O2 was added, the cathodic peak current of the CuO-MWCNTs/GCE remarkably increased while its anodic peak current obviously decreased. By increasing the concentration of H2O2, the cathodic peak current further increased while its anodic peak current further decreased. Indicating CuO-MWCNTs/GCE has a remarkable electrocatalytic activity for H2O2. The scheme. The construction of the MWCNTs-wired CuO nanoflowers modified electrode and electrocatalytic activity towards H2O2 相似文献
11.
A new amperometric biosensor for hydrogen peroxide was developed based on cross-linking horseradish peroxidase (HRP) by glutaraldehyde with multiwall carbon nanotubes/chitosan (MWNTs/chitosan) composite film coated on a glassy carbon electrode. MWNTs were firstly dissolved in a chitosan solution. Then the morphology of MWNTs/chitosan composite film was characterized by field-emission scanning electron microscopy. The results showed that MWNTs were well soluble in chitosan and robust films could be formed on the surface. HRP was cross-linked by glutaraldehyde with MWNTs/chitosan film to prepare a hydrogen peroxide biosensor. The enzyme electrode exhibited excellent electrocatalytic activity and rapid response for H2O2 in the absence of a mediator. The linear range of detection towards H2O2 (applied potential: −0.2 V) was from 1.67 × 10−5 to 7.40 × 10−4 M with correction coefficient of 0.998. The biosensor had good repeatability and stability for the determination of H2O2. There were no interferences from ascorbic acid, glucose, citrate acid and lactic acid. 相似文献
12.
《Electrochemistry communications》2007,9(2):216-220
Direct electrochemical response of Myoglobin (Myb) at the basal plane graphite (BPG) electrode was observed when a room temperature ionic liquid (RTIL), 1-(2-hydroxyethyl)-3-methyl imidazolium tetrafluoroborate ([HEMIm][BF4]), was used as the supporting electrolyte. In a 0.17 M [HEMIm]BF4 aqueous solution, a couple of well-defined redox peaks of Myb could be obtained, whose anodic and cathodic peak potentials were at −0.158 and −0.224 V (vs. Ag/AgCl), respectively. Both anodic and cathodic peak currents increased linearly with the potential scan rate. Compared with the supporting electrolyte of phosphate buffer, [HEMIm][BF4] played an obvious promotion for the direct electron transfer between Myb and the BPG electrode. Further investigation suggested that Myb was adsorbed tightly on the surface of the BPG electrode in the presence of [HEMIm][BF4] to form a stable, approximate monolayer Myb film. Myb adsorbed on the BPG electrode surface showed a remarkable electrocatalytic activity for the reduction of oxygen in a [HEMIm][BF4] aqueous solution. Based on these, a third-generation biosensor could be constructed to directly detect the concentration of oxygen in aqueous solution with a limit of detection of 2.3 × 10−8 M. 相似文献
13.
Hydrogen peroxide is an important analyte in biochemical, industrial and environmental systems. Therefore, development of novel rapid and sensitive analytical methods is useful. In this work, a hemin-graphene nano-sheets (H-GNs)/gold nano-particles (AuNPs) electrochemical biosensor for the detection of hydrogen peroxide (H2O2) was researched and developed; it was constructed by consecutive, selective modification of the GCE electrode. Performance of the H-GNs/AuNPs/GCE was investigated by chronoamperometry, and AFM measurements suggested that the graphene flakes thickness was ∼1.3 nm and that of H-GNs was ∼1.8 nm, which ultimately indicated that each hemin layer was ∼0.25 nm. This biosensor exhibited significantly better electrocatalytic activity for the reduction of hydrogen peroxide in comparison with the simpler AuNPs/GCE and H-GNs/GCE; it also displayed a linear response for the reduction of H2O2 in the range of 0.3 μM to 1.8 mM with a detection limit of 0.11 μM (S N−1 = 3), high sensitivity of 2774.8 μA mM−1 cm−2, and a rapid response, which reached 95% of the steady state condition within 5 s. In addition, the biosensor was unaffected by many interfering substances, and was stable over time. Thus, it was demonstrated that this biosensor was potentially suitable for H2O2 analysis in many types of sample. 相似文献
14.
Based on the immobilization of horseradish peroxidase (HRP) in chitosan(CS) on a glassy carbon electrode (GCE) modified with the Au‐Pt alloy nanoparticles (NPs) / polyaniline nanotube (nanoPAN) nanocomposite film, a novel hydrogen peroxide biosensor was constructed. The modified processes of GCE were monitored by cyclic voltammetry and electrochemical impedance spectroscopy. Au‐PtNPs/nanoPAN/CS had a better synergistic electrochemical effect than did AuNPs/nanoPAN/CS or PtNPs/nanoPAN/CS. The amperometric response of the biosensor towards H2O2 was investigated by successively adding aliquots of H2O2 to a continuous stirring phosphate buffer solution under the optimized conditions. Because Au‐PtNPs have unique catalytic properties and good biocompatibility, and especially Au‐PtNPs and nanoPAN have synergistic augmentation for facilitating electron‐transfer, the biosensor displayed a fast response time (<2 s) and broad linear response to H2O2 in the range from 1.0 to 2200 μmol L?1 with a relatively low detection limit of 0.5 μmol L?1 at 3 times the background noise. Moreover, the biosensor can be applied in practical analysis and exhibited high sensitivity, good reproducibility, and long‐term stability. 相似文献
15.
A novel matrix, gold nanoparticles-bacterial cellulose nanofibers (Au-BC) nanocomposite was developed for enzyme immobilization and biosensor fabrication due to its unique properties such as satisfying biocompatibility, good conductivity and extensive surface area, which were inherited from both gold nanoparticles (AuNPs) and bacterial cellulose nanofibers (BC). Heme proteins such as horseradish peroxidase (HRP), hemoglobin (Hb) and myoglobin (Mb) were successfully immobilized on the surface of Au-BC nanocomposite modified glassy carbon electrode (GCE). The immobilized heme proteins showed electrocatalytic activities to the reduction of H2O2 in the presence of the mediator hydroquinone (HQ), which might be due to the fact that heme proteins retained the near-native secondary structures in the Au-BC nanocomposite which was proved by UV-vis and IR spectra. The response of the developed biosensor to H2O2 was related to the amount of AuNPs in Au-BC nanocomposite, indicating that the AuNPs in BC network played an important role in the biosensor performance. Under the optimum conditions, the biosensor based on HRP exhibited a fast amperometric response (within 1 s) to H2O2, a good linear response over a wide range of concentration from 0.3 μM to 1.00 mM, and a low detection limit of 0.1 μM based on S/N = 3. The high performance of the biosensor made Au-BC nanocomposite superior to other materials as immobilization matrix. 相似文献
16.
《Electrochemistry communications》2007,9(3):469-474
The composite film based on Nafion and hydrophobic room-temperature ionic liquid (RTIL) 1-butyl-3-methyl-imidazolium hexafluorophosphate ([bmim] PF6) was explored. Here, Nafion was used as a binder to form Nafion-ionic liquids composite film and help [bmim] PF6 effectively adhered on glassy carbon (GC) electrode. X-ray photoelectron spectroscopy (XPS), cyclic voltammtery (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize this composite film, showing that the composite film can effectively adhere on the GC electrode surface through Nafion interacting with [bmim] PF6 and GC electrode. Meanwhile, doping [bmim] PF6 in Nafion can also effectively reduce the electron transfer resistance of Nafion. The composite film can be readily used as an immobilization matrix to entrap horseradish peroxidase (HRP). A pair of well-defined redox peaks of HRP was obtained at the HRP/Nafion-[bmim] PF6 composite film-modified GC electrode through direct electron transfer between the protein and the underlying electrode. HRP can still retain its biological activity and enhance electrochemical reduction towards O2 and H2O2. It is expected that this composite film may find more potential applications in biosensors and biocatalysis. 相似文献
17.
A novel biopolymer/room‐temperature ionic liquid composite film based on carrageenan, room temperature ionic liquid (IL) [1‐butyl‐3‐methylimidazolium tetra?uoroborate ([BMIM]BF4)] was explored for immobilization of hemoglobin (Hb) and construction of biosensor. Direct electrochemistry and electrocatalytic behaviors of Hb entrapped in the IL‐carrageenan composite ?lm on the surface of glassy carbon electrode (GCE) were investigated. UV‐vis spectroscopy demonstrated that Hb in the IL‐carrageenan composite ?lm could retain its native secondary structure. A pair of well‐de?ned redox peaks of Hb was obtained at the Hb‐IL‐carrageenan composite ?lm modi?ed electrode through direct electron transfer between the protein and the underlying electrode. The heterogeneous electron transfer rate constant (ks) was 2.02 s?1, indicating great facilitation of the electron transfer between Hb and IL‐carrageenan composite film modi?ed electrode. The modi?ed electrode showed excellent electrocatalytic activity toward reduction of hydrogen peroxide with a linear range of 5.0×10?6 to 1.5×10?4 mol/L and the detection limit was 2.12×10?7 mol/L (S/N=3). The apparent Michaelis‐Menten constant KMapp for hydrogen peroxide was estimated to be 0.02 mmol/L, indicating that the biosensor possessed high af?nity to hydrogen peroxide. In addition, the proposed biosensor showed good reproducibility and stability. 相似文献
18.
Yulin Wang Tianyu Li Weijie Zhang Yaqin Huang 《Journal of Solid State Electrochemistry》2014,18(7):1981-1987
A biosensor with high stability was prepared to determine hydrogen peroxide (H2O2). This hydrogen peroxide biosensor was obtained by modifying glassy carbon electrode (GCE) with a composite film composed of gelatin-multiwalled carbon nanotubes. Catalase (Cat) was covalently immobilized into gelatin-multiwalled carbon nanotubes modified GCE through the well-known glutaraldehyde (GAD) chemistry in order to enhance the stability of electrodes. The enzyme sensor can achieve direct electrochemical response of hydrogen peroxide. The cyclic voltammograms at different scan rates, electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) tests indicate that the enzyme sensor performs positively on increasing permeability, reducing the electron transfer resistance, and improving the electrode performance. The linear response of standard curve for H2O2 is in the range of 0.2 to 5.0 mM with a correlation coefficient of 0.9972, and the detection limit of 0.001 mM. A high operational and storage stability is demonstrated for the biosensor. The peak potential at room temperature in two consecutive weeks stays almost consistent, and the enzyme activity is kept stable even after 30 days in further study. 相似文献
19.
《Electrochemistry communications》2007,9(6):1337-1342
The activity and stability of horseradish peroxidase (HRP) were investigated in a hydrophilic room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluroborate ([bmim][BF4]) by electrochemical methods. Although no detectable activity exhibited in anhydrous [bmim][BF4], HRP was active in the presence of a small amount of water (4.53%, v/v). And its activity can be improved by immobilization in agarose hydrogel. The immobilized HRP possesses excellent activity at 65 °C. It remained 80.2% of its initial activity after being immersed for 10.5 h in an aqueous mixture of [bmim][BF4] with some hydrogen peroxide (H2O2) under room temperature, implying extremely high stability. Moreover, the immobilized HRP was found to be very sensitive and stable in H2O-containing [bmim][BF4] for the detection of H2O2, with a wide linear range of 6.10 × 10−7 to 1.32 × 10−4 mol l−1 and low detection limit of 1.0 × 10−7 mol l−1. 相似文献
20.
A novel method for preparation of hydrogen peroxide biosensor was presented based on immobilization of hemoglobin (Hb) on carbon‐coated iron nanoparticles (CIN). CIN was firstly dispersed in a chitosan solution and cast onto a glassy carbon electrode to form a CIN/chitosan composite film modified electrode. Hb was then immobilized onto the composite film with the cross‐linking of glutaraldehyde. The immobilized Hb displayed a pair of stable and quasireversible redox peaks and excellent electrocatalytic reduction of hydrogen peroxide (H2O2), which leading to an unmediated biosensor for H2O2. The electrocatalytic response exhibited a linear dependence on H2O2 concentration in a wide range from 3.1 μM to 4.0 mM with a detection limit of 1.2 μM (S/N=3). The designed biosensor exhibited acceptable stability, long‐term life and good reproducibility. 相似文献