Synthesis of Cu2+-mediated nano-sized salbutamol-imprinted polymer and its use for indirect recognition of ultra-trace levels of salbutamol

Cu2+-mediated salbutamol-imprinted polymer nanoparticles, synthesized by precipitation polymerization, were mixed with graphite powder and n-eicosane in order to fabricate a modified carbon paste electrode. This electrode was then applied for indirect differential pulse voltammetry determination of salbutamol. In the presence of Cu2+ ions, the formed Cu2+-salbutamol complex was adsorbed in to the pre-designed cavities of the MIP particles, situated on the electrode surface. Since the electrochemical signal of salbutamol was intrinsically small, the oxidation peak of the participant Cu2+, after reduction step, was recorded and used as an indication of salbutamol amount, adsorbed in the electrode. Different variables influencing the sensor performance were studied and the best conditions were chosen for the determination purpose. Correlation between the sensor response to salbutamol and its concentration was linear in the range of 1.0 x 10(-9)-5.5 x 10(-8) M. Detection limit was calculated equal to 6.0 x 10(-10) M (S/N). Five replicated determination of salbutamol (1 x 10(-8)M) resulted in standard error of 3.28%, meaning a satisfactory precision of the determination method. The prepared sensor was applied for real sample analysis. In order to minimize the interference effect, the synthesized polymer was successfully used as a solid phase sorbent for salbutamol extraction, before analysis of real samples by the developed sensor. (C) 2013 Elsevier B.V. All rights reserved.