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The Study On Biosensor Based On Carbon Nano Material And Its Application For Simultaneously Detection Of Two Components

Posted on:2013-06-21Degree:MasterType:Thesis
Country:ChinaCandidate:L HuaFull Text:PDF
GTID:2248330374478218Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
This research was to fabericate a biosensor used for detecting twotypes biological components simultaneously by electrode modifiedwith carbon nanotubes(CNTs). This approach of preparing modifiedelectrodes was simple, cost inexpensive and reproducible, without aprevious separation of the coexistence components which mayinterfere detection. On the other hand, instead of traditional chemistryreduction method, making a breakthrough on reducing grapheneoxide by electrochemical method, a glucose biosensor based ongraphene was developed. This paper includes the following aspects:1. The study on carbon nanotube-based modified electrode and itsapplication for detection of dopamine and ascorbic acidA novel carbon nanotube-based modified electrode(PDDA/SWCNTs/SPCE) has been successfully developed for selectivedetermination of dopamine (DA) in the mixture of DA and ascorbicacid (AA). The modified electrode exhibited superior electrocatalyticactivity towards DA and AA thanks to synergic effect of SWCNTs andPDDA. The separation of oxidation peak potential of DA and AA was180mV. The DPV results showed that the oxidation peak current of DAversus its concentration had a good linearity in the range of10~50μmol/L and50~100μmol/L when the concentration of AA was1mmol/L.This research has accumulated a wealth of valuable experience forsimultaneous determination of medicine molecules.2. The study on carbon nanotube-based modified electrode and itsapplication for simultaneously detection of rutin and ascorbic acidThe electrochemical behaviors of rutin and ascorbic acid atsingle-wall carbon nanotube and polyelectrolytes(dimethyl-diallylammonium chloride, PDDA) film modified glassy carbonelectrode have been investigated. The cyclic voltammetric results showed that electron transfer of rutin at PDDA/SWCNTs/GC modifiedelectrode was an adsorption-controlled process. The separation ofoxidation peak potential of rutin and ascorbic acid is large than200mV.The rutin concentration in the presence of AA were detected bydifferential pulse voltammetry. The experimental results indicated thatPDDA/SWCNTs/GC modified electrode can be used for the detectionof rutin in the presence of high concentration of AA. The DPV resultsshowed that the oxidation peak current of rutin versus its concentrationhad a good linearity in the range of2.5~110μmol/L. The detection limitwas0.5μmol/L. the oxidation peak current of AA versus itsconcentration had a good linearity in the range of0.5~1.5mmol/L. Thedetection limit was0.3mmol/L.3. The study on the glucose biosensor based on graphene modifiedelectrodeGlucose oxidase (GOD) was immobilized steadily onelectrochemically reduced graphene oxide (ERGO) which wasadsorbed on the poly-L-lysine (PLL) modified glassy carbon electrodeby immersed in GO solution. The electrochemical behaviors ofGOD/ERGO/PLL/GC electrode have been investigated by cyclicvoltammetry. Direct electron transfer between GOD immobilized withERGO/PLL and GC electrode was observed. Moreover, theGOD/ERGO/PLL/GC electrode exhibited excellent electrocatalyticactivity for the detection of glucose with a linear range from0.25to4.75mmol/L, the detection limits was0.05mmol/L.
Keywords/Search Tags:carbon nanotubes, graphene, dopamine, ascorbic acid, rutin, glucose oxidase, cyclic voltammetry, differential pulsevoltammetry, simultaneous detection
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