Platinum nanoparticles (PtNPs) were used in combination with multi-walled carbon nanotubes (MWCNTs) with Nafion as the adhesives for fabricating sensitivity-enhanced electrochemical folic acid (FA) sensor. The modifier, PtNPs doped MWCNTs (PtNPs/MWCNTs), was characterized by transmission electron microscopy (TEM) and electrochemical method, it also showed an excellent character for electrocatalytic oxidization of FA. In addition, the experimental parameters such as pH values, the concentration of PtNPs/MWCNTs and the scan rate were optimized. Due to the fine characteristics of PtNPs/MWCNTs, a good linear relationship between the anodic peak current and FA concentration in the range 2.0 x 10(-7)-1.0 x 10(-4) M was observed. The detection limit of 5.01 x 10(-8) M was achieved with the linear correlation coefficient R = 0.9948. The relative standard derivation was 1.9% for 5 x 10(-6) M FA in 11 repeated determinations. This modified electrode showed excellent sensitivity and stability for the determination of FA. (C) 2012 Elsevier B.V. All rights reserved.