SPR Detection of Dopamine Using Cathodically Electropolymerized, Molecularly Imprinted Poly-p-aminostyrene Thin Films

A molecularly imprinted polymer (MIP) film for dopamine (DP) sensing is fabricated from cathodically electrodeposited p-aminostyrene (PAS) on electrode surfaces in a surface plasmon resonance (SPR) spectroscopy setup. The monomer is more commonly used in monolithic MIP free-radical bulk polymerizations. The film growth and rebinding of DP are monitored by electrochemical-SPR (EC-SPR) spectroscopy. UVVis, IR spectroscopy, XPS, AFM, and electrochemistry methods are used to characterize the film. High selectivity against analogous analytes and up to picomolar detection of DP is demonstrated. The reusability of the sensor is also established. Theoretical modeling studies with AM1 calculations predict H-bonding in a stable prepolymerization complex in solution prior to MIP film formation.