Supportless electrochemical sensor based on molecularly imprinted polymer modified nanoporous microrod for determination of dopamine at trace level

Abstract In this work, we developed a novel freestanding metallic microrod as working electrode for highly sensitive and selective electrochemical detection of trace dopamine (DA). The electrode was facilely fabricated via first dealloying smooth Au–Ag alloy microrod (AMR) into nanoporous Au–Ag alloy microrod (NPAMR) and further modifying with electro-polymerized molecularly imprinted polymer (MIP). Influencing factors during electro-polymerization process including pH value and molar ratio of monomer to template molecule were optimized. Under the optimal conditions, a linear range from 2×10 −13 to 2×10 −8  M for measuring DA was obtained with an ultralow detection limit of 7.63×10 −14  M ( S / N =3). In addition, the MIP-modified electrode (MIP/NPAMR) was successfully employed to test DA in serum and brain samples.