title: Simultaneous detection of dopamine, ascorbic acid, and uric acid at electrochemically pretreated carbon nanotube biosensors.
abstract: In this work we have evaluated the performance of electrochemically pretreated single-walled carbon nanotubes (SWCNTs) toward the electrochemical detection of dopamine in the presence of ascorbic acid and uric acid at physiological pH. Results indicated that the electrochemically pretreated SWCNTs showed a selective and enhanced electroanalytical response with minimal electrode fouling toward the detection of dopamine than their untreated counterparts. The observed behavior is attributed to the negatively charged layer present on the SWCNTs originating from the rupture of the basal plane present on the end caps following electrochemical pretreatment. The rupture of basal plane is evident from surface Raman measurements. The negatively charged surface selectively allows the cationic dopamine toward the electrode and repels the anionic ascorbate and uric acid when they coexist in the same solution under physiological pH. A limit of detection of about 15 nM is obtained with these electrodes for the detection of dopamine in the presence of ascorbic acid and uric acid.
  
  
  BACKGROUND
  The performance of electrochemically pretreated single-walled carbon nanotubes (SWCNTs) was studied toward the electrochemical detection of dopamine. These SWCNTs showed a selective and enhanced response toward the detection of dopamine. A limit of detection of about 15 nM is obtained with these electrodes for the detection of dopamine in the presence of ascorbic acid and uric acid.
authors.affiliation: Department of Biomedical Engineering, Florida International University, Miami, Florida 33174, USA.
authors.forename: Subbiah
authors.initials: S
authors.lastname: Alwarappan
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.forename: Chen-Zhong
authors.initials: CZ
authors.lastname: Li
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D004298:Dopamine / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D005898:Glass / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D014527:Uric Acid / Q000032:analysis*
chemical_list: D037742:Nanotubes, Carbon; D014527:Uric Acid; D002244:Carbon; D001205:Ascorbic Acid; D004298:Dopamine