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A novel type of united glucose oxidase (GOD) electrode was designed. Glucose oxidase and ferrocene (Fc), which was a mediator, were added into the composite electrode that was constructed by graphite powder, acetylene black, and epoxy resin. These three materials in composite electrode kept constant proportion in weight. And the optimum amounts of GOD and Fc among united enzyme electrode were 5% and 2%, respectively. The glucose was detected linearly in the concentration range 0.01–9.0 mM with a 20-s steady-state response time and 36 nA/mM of the sensitivity at 0.15 V applied potential. And electrode fouling problem and the response current from the interferents were avoided. The response current of the united GOD electrode had no obvious deterioration within 80 days when stored at 4°C in a refrigerator. The detecting results of human serum by the united GOD electrode had good consistency with that by standard enzyme method. The maximum deviation between these two detecting values was 5%. It might be used for detecting the blood sugar in clinical assay. 相似文献
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聚吡咯葡萄糖氧化酶电极的生物电化学响应 总被引:2,自引:0,他引:2
采用分步骤合过程,制备了以聚吡咯膜为载体的葡萄糖氧化酶电极,探讨了其生物电化学响应特性,计算了酶催化反应的有关动力学参数。与溶解态酶相比,该电极表现出良好的生物电化学特征,而且酶蛋白对溶液温度的稳定性有显著提高。 相似文献
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A. H. Parente E. T. A. Marques W. M. Azevedo F. B. Diniz E. H. M. Melo J. L. Lima Filho 《Applied biochemistry and biotechnology》1992,37(3):267-273
A biosensor for glucose utilizing kinetics of glucose oxidase (EC 1.1.3.4.) was developed. The enzyme was immobilized on polyaniline
by covalent bonding, using glutaraldehyde as a bifunctional agent. The system showed a linear response up to 2.2 mM of glucose
with a response time of 2.5–4.0 min. In addition, the immobilized enzyme had a higher activity between pH 6.5 and 7.5. The
system retained 50% of its activity after 30 d of daily use. The optical absorption spectra of the polyaniline/glucose oxidase
electrode after glucose had been added to the buffer solution showed that the absorption band around 800 nm had changed considerably
when glucose was allowed to react with the electrode. This optical variation makes polyaniline a very promising polymer for
use as a support in optical sensor for clinical application. 相似文献
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Amperometric Choline Sensor with Enzyme Immobilized by Gamma-Irradiation in a Biocompatible Membrane
《Analytical letters》2012,45(13):2455-2470
Abstract An amperometric choline biosensor was constructed using choline oxidase immobilized on poly(2-hydroxyethylmethacrylate) membranes obtained by gamma radiation-induced polymerization at low temperature. The measurements were carried out by Clark-type oxygen or hydrogen peroxide electrodes. Calibration curves were linear in the 10-200 umol · 1?1 range for the oxygen probe and 5-250 umol · 1?1 for the H2O2-based probe. Temperature and pH effects on the activity of immobilized enzyme are described and the response characteristics of the sensor are summarized. The immobilized enzyme membranes stored in glycine buffer or in a dry state were very stable and no significant decrease in the electrode response was observed after three months. The biosensor was employed also to analyse a choline-containing pharmaceutical product and the results were compared to those obtained by enzymatic-spectrophotometric detection. 相似文献
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Polyaniline/Prussian Blue Composite Film Electrochemical Biosensors for Cholesterol Detection 总被引:1,自引:0,他引:1
IntroductionCholesterolisaveryimportantbioactivecompound .Numerousattemptshavebeenmadetocreatesensitive ,selective ,reliableandlowcostcholesterolsensorsduringthelastdecadebecauseofthesignificanceinclinicaldi agnosisofcoronaryheartdiseases ,arterioscleros… 相似文献
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《Electroanalysis》2017,29(7):1741-1748
The determination of lead ions by inhibition of choline oxidase enzyme has been evaluated for the first time using an amperometric choline biosensor. Choline oxidase (ChOx) was immobilized on a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes (MWCNT) through cross‐linking with glutaraldehyde. In the presence of ChOx, choline was enzymatically oxidized into betaine at –0.3 V versus Ag/AgCl reference electrode, lead ion inhibition of enzyme activity causing a decrease in the choline oxidation current. The experimental conditions were optimised regarding applied potential, buffer pH, enzyme and substrate concentration and incubation time. Under the best conditions for measurement of the lowest concentrations of lead ions, the ChOx/MWCNT/GCE gave a linear response from 0.1 to 1.0 nM Pb2+ and a detection limit of 0.04 nM. The inhibition of ChOx by lead ions was also studied by electrochemical impedance spectroscopy, but had a narrower linear response range and low sensitivity. The inhibition biosensor exhibited high selectivity towards lead ions and was successfully applied to their determination in tap water samples. 相似文献
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本采用预活化聚酰膜固定多酚氧化酶并与浸蜡石墨极组合成传感器,测定儿茶酚的线范围2.×10-7-1.25×10^-5mol/L。检出限1.5×10^-7mol/L。酶的固定时间仅需1-2min,5个月之后被固定酶的活性未见下降,活性酶膜的制备,贮存,替换均很方便,对传感器的机理进行了探讨。 相似文献