Composites of multiwalled carbon nanotubes and molecularly imprinted polymers for dopamine recognition

A novel composite of multiwalled carbon nanotubes (MWNTs) and molecularly imprinted polymers (MIPs) was prepared by using dopamine (DA) as a template molecule. Selective copolymerization of methacrylic acid and trimethylolpropane trimethacrylate (copoly(MAA-co-TRIM)) in the presence of DA was achieved at the vinyl group functionalized MWNT surface. Vinyl groups modified on MWNTs surface are a key factor for the formation the composite of MWNTs-MIPs. Attenuated total reflection Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and thermogravimetric analysis were used to characterize the composite structure and determine the grafted MlPs quantities in the composite. The properties such as adsorption dynamics, special binding, and selective recognition capacity were evaluated. The results demonstrated that MWNTs-MIPs not only possessed a rapid dynamic adsorption but also exhibited a high selectivity toward DA, compared to epinephrine. The electrochemical sensor fabricated by modifying MWNTs-MIPs on the glassy carbon electrode could recognize DA from ascorbic acids (AA), indicating DA Could be detected in the presence of AA. And the modified electrode was used to detect the concentration of DA with a linear range of 5.0 x 10(-7) to 2.0 x 10(-1) mol/L.