Determination of metformin based on amplification of its voltammetric response by a combination of molecular wire and carbon nanotubes.
Molecular wires containing copper(II) (CuMW), in the form of the coordination polymer (Cu(II)4(bpp)4(maa)8(H2O)2).2H2O (bpp=1,3-bis(4-pyridyl)propane, maa=2-methylacrylic acid), and multiwalled carbon nanotubes (CNT) have been combined to prepare a paste electrode (CuMW/CNT/PE). The voltammetric response of the CuMW/CNT/PE to metformin (MET) was significantly greater than that of electrodes prepared from other materials, because of both the surface effect of CuMW and CNT and coordination of MET with the Cu(II) ion in the CuMW. A novel voltammetric method for determination of MET is proposed. In pH 7.2 Britton-Robinson buffer, using single sweep voltammetry, the second-order derivative peak current for oxidation of MET at 0.97 V (relative to SCE) increased linearly with MET concentration in the range 9.0 x 10(-7)-5.0 x 10(-5) mol L(-1) and the detection limit was 6.5 x 10(-7) mol L(-1).
Tian
Xin-juan
XJ
Institute of Analytical Science, Northwest University, Xi'an 710069, People's Republic of China.
Song
Jun-feng
JF
Luan
Xin-jun
XJ
Wang
Yao-yu
YY
Shi
Qi-zhen
QZ
D002138:Calibration; D003300:Copper / Q000737:chemistry; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008687:Metformin / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015203:Reproducibility of Results
D004573:Electrolytes; D037742:Nanotubes, Carbon; D003300:Copper; D008687:Metformin