spherical molecularly imprinted polymers using spherical magnetic nanomaterials via electo-polymerization for sensing of levodopa

Abstract: levodopa (l-dopa) is an amino acid precursor of dopamine that is often prescribed to patients suffering from parkinson’s disease. levodopa usage comes with various side effects, including nausea, insomnia, headaches, and elevated heart rate, and is dangerous in high doses [1].molecularly imprinted polymer (mip) is a kind of synthetic material with artificially generated recognition sites which can selectively interact with a target molecule to form closely-related compounds. recently, mip due to prominent selectivity and strong anti-interference ability has been widely used as molecular recognition material in various fields, such as solid phase extraction, drug delivery and biosensors [2]. in particular, both selectivity and adsorption capacity of mips can be elevated to certain extent with carefully selected dual monomers, as the result of increase in polymer-template interaction categories and diversity of functional groups. in addition to the hydrogen bond between the carboxyl group and the pyridyl group, the difunctional monomer can interact with the template polymer through π-π. these monomers can effectively reflect the precise generation of templates and structures. it reminds us that employment of dual functional monomers could increase diversity of the types of blotting sites in mip architecture and therefore enhance affinity by synergistic effects of different monomers. as a result, the obtained dual-monomer mip can effectively enrich targets and eliminate interference, thus improving selectivity of mip to imprinted molecules [3].this work describes a hybrid electrochemical sensor for highly sensitive detection of l-dopa. firstly, magnetic spheres were produced by solvothermal method. then, a spherical molecularly imprinted polymer (smip) was in situ fabricated on magnetic glassy carbon electrode by electro-polymerization, with dopamine and resorcinol as dual functional monomers and l-dopa as template. morphological features and electrochemical properties of smip were investigated in detail. compared with typical one-monomer involving mip, the mip prepared with dual functional monomers showed higher response and better selectivity. under the optimal conditions, a calibration curve of current versus concentration of l-dopa was obtained (0.5–1000 μm with low detection limit of 0.05 μm). determination of l-dopa in real samples was conducted quickly and accurately with the proposed sensor. the smip electrochemical sensor proposed in this work has great potential for drug residue determination in biological fluids.