Development of highly electrocatalytic and electroconducting imprinted film using Ni nanomer for ultra-trace detection of thiamine

The present work describes a new molecularly imprinted polymer-based electrochemical sensor for thiamine (vitamin B 1 ), which has been fabricated exploiting both surface imprinting and nanotechnology. Of two monomers used in this work, N -methacryloylglutamic acid served as a biocompatible and bio-adhesive material, whereas the assistant monomer, acryloylated nickel nanoparticles-functionalized multiwalled carbon nanotubes (Ni nanomer) induced large electro-catalytic and conducting activities to the molecularly imprinted polymer film. The polymer synthesis was carried out, following the ‘surface grafting from’ protocol, with the free radical polymerization directly on the surface of Ni nanomer modified pencil graphite electrode. The presence of functionalized-MWCNTs in the polymer film was inevitable to render stability to the coating via aromatic π − π interactions at the film-nanomer modified electrode interface. Thiamine, being electrochemically inactive, was estimated indirectly by a probe, hexamine ruthenium (II) chloride, with signal transduction via differential pulse anodic stripping voltammetric technique. The limits of detection were in the range 0.17–0.2 ng mL −1 ( S/N = 3) in aqueous, multi-vitamin tablet, urine, and human blood serum, without any cross-reactivity and false- positives. The proposed sensor assures a reliable estimation of thiamine in the patients suffering from its acute deficiency.