Amperometric Determination of Folic Acid at Multi-Walled Carbon Nanotube-Polyvinyl Sulfonic Acid Composite Film Modified Glassy Carbon Electrode

作者：Unnikrishnan, Binesh^*; Yang, Yan-Ling; Chen, Shen-Ming

来源：International Journal of Electrochemical Science, 2011, 6(8): 3224-3237.

• Folic acid
• electrochemical reduction
• multi-walled carbon nanotubes
• cyclic voltammetry
• amperometry

We investigated the electrochemical reduction behavior of folic acid (FA) at multi-walled carbon nanotube-polyvinylsulfonate (MWCNT-PVS) composite film modified glassy carbon electrode (GCE) using cyclic voltammetry (CV). FA undergoes a 2e(-)/2H(+) transfer electrochemical reduction process at -0.7 V with respect to Ag/AgCl reference electrode in pH 7. The reduction peak current increased linearly with the increase in concentration of FA. So far no reports are available for the amperometric determination of FA utilizing the reduction process occurring at negative over potential (-0.7 V). We attempted the amperometric studies making use of this reduction process at -0.7 V. MWCNT-PVS modified electrode showed good amperometric response in the wide linear range from 5.3 x 10(-5) M to 1.7 x 10(-3) M with a sensitivity of 0.1737 mu A mu mol(-1)cm(-2). The surface morphology of MWCNT-PVS film was done by scanning electron microscopy (SEM) and the interfacial electron transfer phenomenon at the modified electrode surface was studied using electrochemical impedance spectroscopy (EIS). The studies showed that MWCNT is well dispersed in PVS and the composite film possesses less electron transfer resistance making it a promising material for electrocatalytic and biosensing applications.

• 出版日期2011-8