Nanostructured conducting molecularly imprinted polymer for selective uptake/release of naproxen by the electrochemically controlled sorbent.

A conducting molecularly imprinted polymer (CMIP) film, based on polypyrrole, was electrosynthesized for selective uptake/release and determination of naproxen. The film was prepared by incorporation of a template anion (naproxen) during the electropolymerization of pyrrole into a platinum electrode using the cyclic voltammetry method. Overoxidized polypyrrole films with cavities complementary to the template were used as a potential-induced selective recognition element in the solid-phase sorbent. Various important fabricating factors, which control the performance of the CMIP film, were investigated using fluorescence spectroscopy. The measured fluorescence intensities of released solutions were related to the concentrations of naproxen taken up into the films. Several key parameters such as applied potential and time for uptake and release were varied to achieve the optimal sorption procedure. The film template with naproxen exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5 × 10⁻⁸ to 3 × 10⁻⁷ mol ml⁻¹ and 7 × 10⁻⁶ to 8 × 10⁻⁴ mol ml⁻¹, and the limit of detection was 1 × 10⁻⁸ mol ml⁻¹. The CMIP films, as the electrochemically controlled solid-phase sorbent, were applied for the selective cleanup and quantification of trace amounts of naproxen from physiological samples. Scanning electron microscopy confirmed the nanostructure morphology of the films.