Study of carbon nanotube modified biosensor for monitoring total cholesterol in blood

Li, G.; Liao, Jiancong; Hu, Guoqing; Ma, Nanke; Wu, Ping

doi:10.1016/j.bios.2004.09.005

Cited by 212 publications

(92 citation statements)

References 13 publications

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“…The sensitivity over the linear range was 17.1 ± 0.4 mA M -1 cm -2 , which is higher than the most advanced systems such as those based on osmium-based hydrogel (Ohara et al 1993). A good linear relationship between current density and cholesterol concentration was obtained from 0.015 to 1 mM cholesterol that corresponds to the free cholesterol concentrations in blood (Li et al 2005). The sensitivity was found to be 40 ± 2 mA M -1 cm -2 (r = 0.995) and the detection limit 2.3 μM (Inset to Figure 4 C).…”

Section: Immobilisation Of Different Mediated Oxidasesmentioning

confidence: 79%

Unsubstituted phenothiazine as a superior water-insoluble mediator for oxidases

Sekretaryova

Vagin

Beni

et al. 2014

Biosensors and Bioelectronics

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The mediation of oxidases: glucose oxidase (GOx), lactate oxidase (LOx) and cholesterol oxidase (ChOx) by a new electron shuttling mediator, unsubstituted phenothiazine (PTZ), was studied. Cyclic voltammetry and rotating-disk electrode measurements in nonaqueous media were used to determine the diffusion characteristics of the mediator and the kinetics of its reaction with GOx, giving a second-order rate constant of 7.6 × 10 3 M -1 s -1 to 2.1 × 10 4 M -1 s -1 for water -acetonitrile solutions containing 5 % to 15 % water. These values are in the range reported for commonly used azine-type mediators, indicating that PTZ is able to function as an efficient mediator. PTZ and GOx, LOx and ChOx were successfully co-immobilized in sol-gel membrane on a screen-printed electrode to construct glucose, lactate and cholesterol biosensors, respectively, which were then optimised in terms of stability and sensitivity. The electrocatalytic oxidation responses showed a dependence on substrate concentration ranging from 0.6 to 32 mM for glucose, from 19 to 565 mM for lactate and from 0.015 to 1.0 mM for cholesterol detection.Oxidation of substrates on the surface of electrodes modified with PTZ and enzyme membrane was investigated with double-step chronoamperometry and the results showed that the PTZ 2 displays excellent electrochemical catalytic activities even when immobilised on the surface of the electrode. Highlights: The kinetics of the electrocatalytic oxidation of glucose with GOx mediated by a new electron shuttling mediator, PTZ, was studied. PTZ delivers superior potential performance among azine-type redox mediators for GOx. PTZ and GOx, LOx and ChOx were successfully co-immobilized in sol-gel membrane on a screen-printed electrode to construct glucose, lactate and cholesterol biosensors, respectively. Second-order rate constants for the reaction between the mediator and variety of oxidases co-immobilised inside a sol-gel membrane were obtained by chronoamperometry.

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Section: Immobilisation Of Different Mediated Oxidasesmentioning

confidence: 79%

Unsubstituted phenothiazine as a superior water-insoluble mediator for oxidases

Sekretaryova

Vagin

Beni

et al. 2014

Biosensors and Bioelectronics

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show abstract

“…Different matrix compositions and techniques have been used to achieve enzyme immobilization over the years [80]. [85]. The magnetic fluorescent SiO 2 nanoparticles were used for CHOx immobilization, which were reported to improve thermal, storage and operational stabilities of immobilized CHOx [97].…”

Section: Purification Strategies For Cholesterol Oxidasementioning

confidence: 99%

Cholesterol Oxidase: Source,Properties and Applications.

Devi¹,

Kanwar²

2018

Insights Enzyme Res

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“…At this stage of development, the performances of the biosensor remained constant for 1 week, but decreased 10-fold after 1 month and vanished after 2 months. A third technique of fabrication was applied to carbon nanoelectrodes for monitoring total cholesterol in blood [186]. Cholesterol oxidase, peroxidase, potassium ferrocyanide and threhalose dissolved in a buffer were deposited onto the reaction area of the electrode.…”

Section: Nanoelectrode Biosensorsmentioning

confidence: 99%

“…3.7). A third approach to fabricate the electrodes was based on the utilization of the SPE technique [185,186]. The working and the reference electrodes were made of carbon paste.…”

Section: Fabricationmentioning

confidence: 99%