title: Direct electrochemical determination of morphine on a novel gold nanotube arrays electrode.
abstract: BACKGROUND
  Morphine (MP), a group of narcotic pain relieve drugs, is frequently used to relieve severe pain for patients, especially for those who undergo a surgical procedure. However, when overdosed or abused, MP is toxic and can cause disruption in the central nervous system. Therefore, to prevent overdose-induced toxication, it is necessary to sensitively determine the concentrations of MP in patient's blood or urine.
  
  
  METHODS
  We report an easy-to-use approach for directly electrodepositing gold nanotube arrays onto an anodic aluminum oxide template (AAO) by performing cyclic voltammetry for a short period of time. Morphological characterization of gold nanotubes demonstrates that the inner diameter of gold nanotubes becomes smaller upon the increase of deposition time. An electrochemical sensor for direct determination of morphine was constructed by attaching gold nanotube arrays onto the surface of a glassy carbon electrode (GCE).
  
  
  RESULTS
  The resulting electrochemical sensor offers an excellent response for morphine in the concentration range of 1.22×10(-7) - 7.44×10(-4) mol/l with a detection limit of 4.06×10(-8) mol/l and a correlation coefficient of 0.995.
  
  
  CONCLUSIONS
  The electrochemical sensor shows good regeneration, stability and selectivity and has been used for the determination of morphine in serum samples with satisfied results.
authors.affiliation: College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, PR China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Yang
authors.forename: Yaqian
authors.initials: Y
authors.lastname: Chen
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Yang
mesh_terms: D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D009020:Morphine / Q000032:analysis* / Q000097:blood / Q000652:urine; D043942:Nanotubes; D015203:Reproducibility of Results
chemical_list: D006046:Gold; D009020:Morphine