Bibliographic Information Self-gelatinizable copolymer immobilized glucose biosensor based on prussian blue modified graphite electrode

Bibliographic Information
Electrochemical preparation of microelectrodes modified with non-stoichiometric mixed-valence molybdenum oxides. Wang, BaoXing; Hu, Gang; Liu, BaiFeng; Dong, ShaoJun. Inst. of Applied Chem., Chinese Academy of Sci., Changchun, Peop. Rep. China. Huaxue Xuebao (1996), 54(6), 598-604. CODEN: HHHPA4 ISSN: 0567-7351. Journal written in Chinese. CAN 125:206779 AN 1996:434146 CAPLUS (Copyright 2001 ACS)
Abstract
A compact non-stoichiometric molybdenum(VI,V) oxide of blue film was grown on carbon fiber (CF) microelectrode surface by cycling the potential between +0.2V and -0. 70 V in a freshly prepd. Na2MoO4 soln. contg. 5 ´ 10-3 mol/L H2SO4. The quantity of the oxide is controlled by the charge passing the electrode. The electrochem. pretreatment of CF microelectrode not only raises the deposition velocity of molybdenum oxide on CF surface, but also improves greatly the cyclic voltammetric behavior of the molybdenum oxide film prior to the electrodeposition. The cathodic processes are believed to yield the hydrogen molybdenum oxide bronzes, HxMoO3(0 < x < 2), or substoichiometric lower molybdenum oxides with the formula MoO3-y (0 < y < 1). The anodic response results from the reversible oxidn. of molybdenum bronze/Mo(V) centers [or perhaps Mo(IV) in more reduced coatings] to Mo(VI). Further information was gained about the chem. compn. and valence state of Mo from XPS and SEM.
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Orientation and electrocatalysis of riboflavin adsorbed on carbon substrate surfaces. Zhang, Jingdong; Chi, Qijin; Dong, Shaojun; Wang, Erkang. Lab. Electroanal. Chem., Chinese Acad. Sci., Changchun, Peop. Rep. China. J. Chem. Soc., Faraday Trans. (1996), 92(11), 1913-1920. CODEN: JCFTEV ISSN: 0956-5000. Journal written in English. CAN 125:126010 AN 1996:392475 CAPLUS (Copyright 2001 ACS)
Abstract
Based on scanning tunneling microscopy and electrochem. measurements, the orientation and electrocatalytic function of riboflavin adsorbed on C substrates are described for the first time. Scanning tunneling micrographs show clearly that tip induction may result in an orientation change of the adsorbed riboflavin mol. on highly oriented pyrolytic graphite from the initially vertical orientation to the stable flat form. The adsorbed riboflavin as an effective mediator can accelerate the redn. of dioxygen which accepts two electrons from the reduced riboflavin to generate H2O2. The rate consts. of the electrocatalytic reaction in various pH solns. were detd. by using a rotating disk electrode modified with riboflavin. The pH effect and possible catalytic mechanism are discussed.
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The electrochemical behavior of Eastman AQ/Meldola blue-coated microelectrodes. Tian, Min; Dong, Shaojun. Changchun Inst. Applied Chem., Chinese Academy Sciences, Changchun, Peop. Rep. China. Electroanalysis (1996), 8(5), 454-459. CODEN: ELANEU ISSN: 1040-0397. Journal written in English. CAN 125:125981 AN 1996:358847 CAPLUS (Copyright 2001 ACS)
Abstract
Eastman-AQ 55D was coated onto a carbon fiber microelectrode surface, and the resulting modified electrodes exhibited high stability. Substantial improvement in the stability was obsd. as a result of good adhesion and the strong binding of large hydrophobic cations of Eastman AQ 55D. The electrode reaction of Meldola blue bound in the polymer film showed a reversible, 1-electron transfer process. The effects of soln. pH and influence of supporting electrolyte on the modified carbon fiber microelectrode are discussed. The diffusion coeff. of Meldola blue in the AQ polymer film detd. by chronoamperometry is 2.3 ´ 10-8 cm2 s-1, and the heterogeneous rate const. of Meldola blue at the AQ polymer film/electrode detd. by normal pulse voltammetry is 3.97 ´ 10-3 cm s-1.
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Improvements in the Selectivity of Electrochemical Detectors for Liquid Chromatography and Flow Injection Analysis Using the Self-Assembled n-Alkanethiol Monolayer-Modified Au Electrode. Liu, Zhiming; Li, Jinghong; Dong, Shaojun; Wang, Erkang. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Peop. Rep. China. Anal. Chem. (1996), 68(14), 2432-2436. CODEN: ANCHAM ISSN: 0003-2700. Journal written in English. CAN 125:25490 AN 1996:338337 CAPLUS (Copyright 2001 ACS)
Abstract
4-Aminophenol (4-AP), paracetamol (PRCT), norepinephrine (NE) and dopamine (DA) (all somewhat hydrophobic compds.) were HPLC electrochem. detected while the signals from uric acid (UA) and ascorbic acid (AA) (both hydrophilic compds. at the pH studied), were minimized taking advantage of the permselectivity of the self-assembled n-alkanethiol monolayer (C10-SAM)-modified Au electrodes based on solute polarity. The effects of various factors, such as the chain length of the n-alkanethiol modifier, modifying time, and pH value, on the permeability of C10-SAM coatings were examd. The calibration curves, linear response ranges, detection limits, and reproducibilities of the EC detector for 4-AP, PRCT, NE, and DA were obtained. The result shows that the EC detector can be applied in the chromatog. detection of 4-AP, PRCT, NE, and DA in urine, effectively removing the influence of UA and AA in high concns. existing in biol. samples. As a result, a great improvement in the selectivity of EC detectors has been achieved by using Au electrodes coated with neutral n-alkanethiol monolayer.
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Probe beam deflection study of cupric hexacyanoferrate colloid doped polypyrrole film modified electrode in different electrolytes. Liu, Changwei; Cheng, Guangjin; Li, Jinghong; Jin, Juguang; Dong, Shaojun. Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, Peop. Rep. China. J. Electroanal. Chem. (1996), 407(1-2), 243-246. CODEN: JECHES ISSN: 0368-1874. Journal written in English. CAN 125:70116 AN 1996:320554 CAPLUS (Copyright 2001 ACS)
Abstract
Electroactive cupric hexacyanoferrate colloid (as a dopant anion) is immobilized in the polypyrrole (PPy) matrix. Probe beam deflection (PBD) combined with cyclic voltammetry (CV) techniques is a powerful tool for detecting the ion exchange mechanism of this film. The ion exchange accompanied by the redox dopant anions is conserved by intake/expulsion of electrolyte cations as NH4+ and K+, whereas Na+ and Li+ ions cannot enter the film freely. At the same potential range, the partial overoxidn. of PPY film is followed by intake/expulsion of electrolyte anions to maintain its electroneutrality.
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Electrochemical behavior of the molybdotungstate heteropoly complex with neodymium, K10H3[Nd(SiMo7W4O39)2]×xH2O in aqueous solution. Cheng, Long; Zhang, Xiumei; Xi, Xiaodan; Liu, Baifeng; Dong, Shaojun. Department of Chemistry, Harbin Engineering University, Harbin, Heilongjiang, Peop. Rep. China. J. Electroanal. Chem. (1996), 407(1-2), 97-103. CODEN: JECHES ISSN: 0368-1874. Journal written in English. CAN 125:70103 AN 1996:320534 CAPLUS (Copyright 2001 ACS)
Abstract
The electrochem. behavior of the title compd. (denoted Nd(SiMo7W4)213-) in aq. soln. was studied using cyclic voltammetry, sampled d.c. voltammetry, differential pulse voltammetry and bulk electrolysis with coulometry. The stable pH range of Nd(SiMo7W4)213- is detd. with UV-visible spectra. In the potential range between 0.70 and -0.45 V vs. SCE, the anion in pH 3.8 aq. soln. undergoes 1-, 1-, 2- and 2-electron steps of four redox processes attributed to electron addn. and removal from the molybdate-oxo framework. The adsorption of the anion on the dropping mercury electrode and a self-inhibition influence of the adsorbed anions on the redox process of those anions dissolved in soln. are found. The unusual dependence of the formal potentials on pH is explained with the competition of the protonation and ion-pair formation due to the high neg. charge of Nd(SiMo7W4)213- and its reduced forms. The electrocatalytic effects of the anion on the bromate were studied.
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Electrochemical study of isopoly- and heteropolyoxometallate film modified microelectrodes. Part 7. Preparation and electrochemical behavior of 1:2:10-molybdovanodophosphate [PV2Mo10]-type and PV2Mo10/polyaniline films modified carbon fiber microelectrodes. Wang, Baoxing; Dong, Shaojun. Institute Applied Chemistry, Chinese Academy Sciences, Changchun, Peop. Rep. China. Fenxi Huaxue (1996), 24(4), 382-6. CODEN: FHHHDT ISSN: 0253-3820. Journal written in Chinese. CAN 124:354896 AN 1996:257218 CAPLUS (Copyright 2001 ACS)
Abstract
The prepn. and electrochem. behavior of the carbon fiber (CF) microelectrodes modified with PV2Mo10 thin film or PV2Mo10/PAn film are described in detail. These modified electrodes have high stability and redox activity in aq. acidic medium. The PV2Mo10 can be strongly adsorbed on the surface of CF microelectrode. The pH of the electrolyte soln. and the scanning potential range greatly influence the stability and electrochem. properties of the PV2Mo10 thin film or the PV2Mo10/PAn film modified on CF microelectrodes. The thickness of the film and the amt. of dopant in the PAn film can be controlled by the exptl. parameters such as the charge, time and the ratio of aniline to PV2Mo10 in the modification soln. The CF microelectrode with PV2Mo10/PAn film possesses a strong catalytic effect on the redn. of chlorate and bromate anions in the soln.
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Synthesis of N-(n-octyl)-N'-(10-mercaptodecyl)-4,4'-bipyridinium dibromide and electrochemical behavior of its monolayers on a gold electrode. Yan, Juchao; Li, Jinghong; Chen, Wenqi; Dong, Shaojun. Changchun Inst. of Applied Chemistry, Chinese Academy of Sciences, Jilin, Peop. Rep. China. J. Chem. Soc., Faraday Trans. (1996), 92(6), 1001-6. CODEN: JCFTEV ISSN: 0956-5000. Journal written in English. CAN 124:300779 AN 1996:212944 CAPLUS (Copyright 2001 ACS)
Abstract
A new viologen deriv. of N-(n-octyl)-N'-(10-mercaptodecyl)-4,4'-bipyridinium dibromide was prepd. and characterized by elemental anal., IR, 1H NMR, MS and TG-DTA. XPS, cyclic voltammetry and chronoamperometry were used to characterize the monolayers formed by this compd. on the bulk gold electrodes by self-assembly.
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The direct electrochemistry of cytochrome c at the nanometer-sized rare earth element oxide particle-modified gold electrodes. Qu, Xiaogang; Dong, Xiangting; Cheng, Ziyong; Lu, Tianhong; Dong, Shaojun. Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Peop. Rep. China. J. Mol. Catal. A: Chem. (1996), 106(1-2), 1-5. CODEN: JMCCF2 ISSN: 1381-1169. Journal written in English. CAN 124:255061 AN 1996:201260 CAPLUS (Copyright 2001 ACS)
Abstract
The direct electrochem. of cytochrome c was studied at nanometer-sized rare earth element dioxide particle-modified gold electrodes. It was demonstrated that rare earth element oxides can accelerate the electrochem. reaction of cytochrome c and the reversibility of the electrochem. reaction of cytochrome c was related to the size of rare earth element oxide particles.
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In situ electrochemical scanning tunnelling microscopy investigation of structure for horseradish peroxidase and its electrocatalytic property. Zhang, Jingdong; Chi, Qijin; Dong, Shaojun; Wang, Erkang. Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, Peop. Rep. China. Bioelectrochem. Bioenerg. (1996), 39(2), 267-74. CODEN: BEBEBP ISSN: 0302-4598. Journal written in English. CAN 124:311127 AN 1996:200686 CAPLUS (Copyright 2001 ACS)
Abstract
Immobilization of protein mols. is a fundamental problem for scanning tunneling microscopy (STM) measurements with high resoln. In this paper, an electrochem. method has been proved to be an effective way to fix native horseradish peroxidase (HRP) as well as inactivated HRP from electrolyte onto a highly oriented pyrolytic graphite (HOPG) surface. This prepn. is suitable for both ex situ and in situ electrochem. STM (ECSTM) measurements. In situ STM has been successfully employed to observe totally different structures of HRP in three typical cases: (1) in situ ECSTM reveals an oval-shaped pattern for a single mol. in neutral buffer soln., which is in good agreement with the dimension detd. as 6.2 ´ 4.3 ´ 1.2 nm3 by ex situ STM for native HRP; (2) in situ ECSTM shows that the adsorbed HRP mols. on HOPG in a denatured environment exhibit swelling globes at the beginning and then change into a V-shaped pattern after 30 min; (3) in situ ECSTM reveals a black hole in every ellipsoidal sphere for inactivated HRP in strong alkali soln. The cyclic voltammetry results indicate that the adsorbed native HRP can directly catalyze the redn. of hydrogen peroxide, demonstrating that a direct electron transfer redn. occurred between the enzyme and HOPG electrode, whereas the corresponding cyclic voltammograms for denatured HRP and inactivated HRP adsorbed on HOPG electrodes indicate a lack of ability to catalyze H2O2 redn., which confirms that the HRP mols. lost their biol. activity. Obviously, electrochem. results powerfully support in situ STM observations.
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Electrochemical study of isopoly- and heteropoly-oxometallates film modified microelectrodes-VI. Preparation and redox properties of 12-molybdophosphoric acid and 12-molybdosilicic acid modified carbon fiber microelectrodes. Wang, Baoxing; Dong, Shaojun. Laboratory Electroanalytical Chemistry, Changchun Institute Applied Chemistry, Changchun, Jilin, Peop. Rep. China. Electrochim. Acta (1996), 41(6), 895-902. CODEN: ELCAAV ISSN: 0013-4686. Journal written in English. CAN 124:273003 AN 1996:195441 CAPLUS (Copyright 2001 ACS)
Abstract
The redox behaviors of 12-molybdophosphoric acid (12-MPA) and 12-molybdosilicic acid (12-MSA) in aq. acid media were characterized at the carbon fiber (CF) microelectrode. The prepn. of CF microelectrode modified with 12-MPA or 12-MSA monolayer and the oxidn.-redn. properties of the modified electrode in aq. acid media or 50% (vol./vol.) water-org. media contg. some inorg. acids were studied by cyclic voltammetry. 12-MPA or 12-MSA monolayer modified CF microelectrode with high stability and redox reversibility in aq. acidic media can be prepd. by simple dip coating. The cyclic voltammograms of 12-MPA and 12-MSA and their modified CF microelectrodes in aq. acid soln. exhibit three two-electron reversible waves with the same half-wave potentials, which defines that the species adsorbed on the CF electrode surface are 12-MPA and 12-MSA themselves. The acidity of electrolyte soln., the org. solvents in the electrolyte soln., and the scanning potential range strongly influence on the redox behaviors and stability of 12-MPA or 12-MSA monolayer modified electrodes. However, the catalytic effects of the 12-MPA and 12-MSA and chlorate anions in aq. acidic soln. on the electrode reaction processes of 12-MPA or 12-MSA are described.
Bibliographic Information
Direct electrochemical identification of an activated intermediate formed by cytochrome C with hydrogen peroxide. Zhu, Yimin; Li, Jinghong; Dong, Shaojun. Lab. Electroanal. Chem., Changchun Inst. Appl. Chem., Chinese Acad. Sci., Changchun, Peop. Rep. China. Chem. Commun. (Cambridge) (1996), (1), 51-2. CODEN: CHCOFS ISSN: 1359-7345. Journal written in English. CAN 124:224162 AN 1996:151844 CAPLUS (Copyright 2001 ACS)
Abstract
An activated intermediate formed from H2O2 and cytochrome C is identified by direct electrochem. measurements.
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A study of the dependence of ferrocene diffusion on electrolyte concentration and size in a polymer medium using non-steady-state chronoamperometry. Dong, Shaojun; Zhou, Huafang. Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, Peop. Rep. China. J. Electroanal. Chem. (1996), 403(1-2), 117-23. CODEN: JECHES ISSN: 0368-1874. Journal written in English. CAN 124:244840 AN 1996:142825 CAPLUS (Copyright 2001 ACS)
Abstract
This article describes a quant. study of the diffusion rate of ferrocene(Fc) dissolved in ploy(ethylene glycol)(PEG) medium contg. MClO4(M = Li+, Na+, Bu4N+, Hx4N+). The apparent diffusion coeff. Dapp and the active concn. ca of Fc were simultaneously measured by using non-steady-state chronoamperometry. The Dapp and ca of Fc were estd. in PEG contg. different concns. and sizes of supporting electrolyte, and the dependence of Dapp on ferrocene concns. was obsd. The values of Dapp decrease with increasing concns. of Fc, increasing concns. of LiClO4 or the ratio (O : Li) and also with decreasing cation radius of the electrolyte. The temp. dependencies conform to a simple free vol. model. The concn. and size of the counterion dependencies of the diffusion rate are similar to the behavior of their dependencies of ionic cond. in polyelectrolyte.
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Electrochemically controlled release of 5-fluorouracil. Huang, Hua; Liu, Baifeng; Dong, Shaojun. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Peop. Rep. China. Fenxi Huaxue (1996), 24(2), 130-4. CODEN: FHHHDT ISSN: 0253-3820. Journal written in Chinese. CAN 124:211803 AN 1996:127495 CAPLUS (Copyright 2001 ACS)
Abstract
The electrochem. controlled release of 5-fluorouracil (5-FU) from the polypyrrole (PPy) film on glassy carbon electrode is described. The release of 5-FU from the PPy film depends on the electrochem. redox process of the PPy film. The release amt. is controlled by redn. potential, and the amt. of 5-FU released in proportional to the cathodic charge and thickness of the film. The exchange of 5-FU anions with chloride ions at an open circuit is slow on the time scale of minutes, but release of the 5-FU anions can be completed in 100 s at -0.6V (vs. Ag/AgCl).
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Cyro-hydrogel for the construction of a tyrosinase-based biosensor. Deng, Qing; Guo, Yizhu; Dong, Shaojun. Changchun, Peop. Rep. China. Anal. Chim. Acta (1996), 319(1-2), 71-7. CODEN: ACACAM ISSN: 0003-2670. Journal written in English. CAN 124:197529 AN 1996:79440 CAPLUS (Copyright 2001 ACS)
Abstract
A new immobilization method for construction of a tyrosinase based biosensor is described. A simple phys. freezing technique was adopted for prepn. The immobilized enzyme yields specific activities that are more than 22% of the sol. enzyme. The enzyme electrode can be stored in dry state for more than three months without any loss of activity. The biosensor was applied to the detn. of several phenols and o-diphenols. The lowest detect limit is 0.02 mmol/l and the linear range was 1.0´10-7-1.0´10-4 mol/l for catechol. The kinetic parameters have also been calcd.
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Dynamic spectroelectrochemical measurement for the conformational transition of cytochrome c induced by bromopyrogal red. Zhu, Yimin; Niu, Jianjun; Dong, Shaojun. Jilin, Peop. Rep. China. Bioelectrochem. Bioenerg. (1996), 39(1), 95-100. CODEN: BEBEBP ISSN: 0302-4598. Journal written in English. CAN 124:138992 AN 1996:58530 CAPLUS (Copyright 2001 ACS)
Abstract
The conformational transition of horse heart cytochrome c induced by bromopyrogal red (BPR) in very low concn. has been firstly investigated by dynamic spectroelectrochem. technique, both at the BPR adsorbed platinum gauze electrode and at a bare platinum gauze electrode in a soln. contg. BPR. The effect of BPR on the structure of cytochrome c was studied by UV-visible and Fourier transform IR spectroscopy. The unfolded cytochrome c behaves simply as an electron transfer protein with a formal potential of -142 mV vs. a normal hydrogen electrode. The difference between the formal potentials of the native and unfolded cytochrome c is coupled to a difference in conformational energy of the two states of about 40 kJ mol-1, which agrees well with the result reported. The stability and slow refolding of the unfolded cytochrome c are discussed.
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Kinetics of electrocatalytic ascorbic acid at ultramicroelectrode modified by Eastman-AQ polymer containing tris(2,2'-bipyridine) osmium(III/II) complexes as electron-transfer centers. Che, Guangli; Dong, Shaojun. Lab. Electroanalytical Chem., Chinese Academy of Sciences, Changchun, Peop. Rep. China. Electrochim. Acta (1996), 41(3), 381-8. CODEN: ELCAAV ISSN: 0013-4686. Journal written in English. CAN 124:129715 AN 1996:27529 CAPLUS (Copyright 2001 ACS)
Abstract
The theor. model[17] of an ultramicroelectrode modified with a redox species film was used as the diagnostic tool to characterize the catalytic oxidn. of ascorbic acid at C fiber ultramicro-disk electrodes coated with an Eastman-AQ-Os(bpy)32+ film. The electrocatalytic behavior of ascorbic acid at the ultramicroelectrode modified by an Eastman-AQ polymer (AQ 29D) contg. tris(2,2'-bipyridine) Os(III/II) as mediators is described. To det. the five characteristic currents quant., the radius of the ultramicroelectrode and the concn. of ascorbic acid are varied systematically. The kinetic zone diagram was used to study the electrocatalytic system. This system with 0.5-2.75 mM ascorbic acid belongs to SR + E case, and the concn. profile of the catalyst in the film are given. Finally, optimizing the design of catalytic system is discussed.