Electrosynthesized nanostructured molecularly imprinted polymer for detecting diclofenac molecule

This work describes the preparation and application of micropatterned molecular imprinting in conductive polymer film for the detection of diclofenac molecules. A fast and cost-effective technique for generating nanos-tructured polymer on glassy carbon electrode (GCE) by combining nanosphere lithography (NSL) and electro-chemical polymerization is reported. Firstly, GCE is modified by a close-packed monolayer of polystyrene (PS) spheres sized 500 nm in diameter, which subsequently serves as a template for the electrochemical deposition of poly(3,4-ethylene dioxythiophene) (PEDOT) accompanied by diclofenac (DCF). The functional monomers of 3,4-ethylene dioxythiophene (EDOT) were electropolymerized in the presence of sodium diclofenac (DCF-Na) as a target molecule to prepare a molecularly imprinted polymer (MIP) electrode. After dissolving PS and DCF-templated molecules simultaneously in tetrahydrofuran (THF) solvent, the micropatterned structure of PEDOT is generated on the GCE surface. This as-prepared MIP surface is applied to test the recognition of DCF mole-cules in phosphate-buffered saline (PBS) solution. Good linearity of peak current recorded by differential pulse voltammograms (DVP) after exposure to different DCF concentrations was obtained with a limit of detection (LOD) of 77.5 nM. The sensitivity of the as-prepared MIP electrode is 5 times larger than that of the control electrode made by non-molecular imprinted polymer (NIP). It opens a pathway to significantly improve the sensitivity and the quality of conventional electrochemical sensors for the detection of Diclofenac.