Ultrastable method for determination of folic acid based on polyneutral red and multiwalled carbon nanotubes composite nanofilm

By using the electrocatalytic property of the nanomaterials and the molecular recognition characteristic of neutral red (NR), a new modified electrode was fabricated by electropolymerising the NR onto the surface of the multiwalled carbon nanotubes modified glassy carbon electrode, which exhibited a good electrocatalytic activity for folic acid (FA). The results of experiments showed that a good linear relationship between the reductive peak current of FA and its concentration was in the range of 6.25 × 10 −7 –5.00 × 10 −5 mol/l with a detection limit of 1.37 × 10 −7 mol/l in the optimal conditions. The recovery ratio was in the range of 99.3 ∼ 103.2%. The composite film modified electrode exhibited an excellent stability with a simple fabrication, which established a solid foundation for the practical applications.