Surface modified multiwalled carbon nanotube based molecularly imprinted polymer for the sensing of dopamine in real samples using potentiometric method

The aim of this work was to test the application of multi-walled carbon nanotube based molecularly imprinted polymer (MWCNTs-MIP) for the determination of dopamine (DA) in blood serum and urine samples. The acrylamide grafted MWCNTs with vinyl group (MWCNTs-g-AAm-CHCH2) was prepared by free radical graft copolymerization technique. MIP was synthesized by selective polymerization of MWCNTs-g-AAm-CHCH2 with itaconic acid (IA) as functional monomer in the presence of DA using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and α,α′-azobisisobutyronitrile (AIBN) as the initiator. The response time was ∼2 min and the detection limit was 1.0 × 10−9 mol L−1, so the proposed sensor could be considered as a sensitive marker of DA depletion in Parkinsonʹs disease. The MWCNTs-MIP sensor demonstrated a high selectivity, sensitivity and stability, in addition to that good reproducibility. The useful lifetime for the DA sensor was longer than 2 months and the sensor was successfully tested in real samples.