US EPA

5167530 

Journal Article 

Novel electrochemical method for sensitive determination of homocysteine with carbon nanotube-based electrodes 

Gong, K; Dong, Y; Xiong, S; Chen, Y; Mao, L 

2004 

Yes 

Biosensors and Bioelectronics
ISSN: 0956-5663
EISSN: 1873-4235 

20 

2 

253-259 

English 

15308229 

10.1016/j.bios.2004.01.014 

WOS:000224034400016 

An electrochemical method has been successfully demonstrated for sensitive determination of homocysteine (HcySH) with carbon nanotube (CNT)-modified glassy carbon (GC) electrodes. Cyclic voltammetric results clearly show that carbon nanotubes, especially those pretreated with nitric acid, possess an excellent electrocatalytic activity toward the oxidation of HcySH at a low potential (0.0 V versus Ag/AgCl). The remarkable catalytic property of the acid-pretreated CNTs, which is essentially associated with oxygen-containing moieties introduced on the tube surface, has been further exploited as a sensitive determination scheme for HcySH. Continuous-flow amperometric results suggest that the CNT-based electrodes (p-CNT/Nafion/GC), which were prepared by using Nafion to solubilize and further immobilize CNTs on GC electrodes, show striking analytical properties of good stability and reproducibility and strong ability against electrode fouling. Such analytical properties, along with the low operation potential, substantially enable a reliable and sensitive determination of HcySH with a good dynamic linearity up to 60 microM and a detection limit of 0.06 microM (S/N = 3). The catalytic mechanism and the possible application of the as-prepared p-CNT/Nafion/GC electrodes for the study of the auto-oxidation of HcySH are also demonstrated and discussed.