A dual usage smart sorbent/recognition element based on nanostructured conducting molecularly imprinted polypyrrole for simultaneous potential-induced nanoextraction/determination of ibuprofen in biomedical samples by quartz crystal microbalance sensor

A selective detection strategy presented for ibuprofen (IBP) as a model anionic drug based on potential-induced uptake/release of the drug by a smart conducting molecularly imprinted polymer (CMIP) as sorbent/recognition element for simultaneous nanoextraction and determination of IBP in plasma samples by quartz crystal microbalance (QCM) without any additional treatment. The nanostructured CMIP film was directly synthesized by cyclic voltammetry method on the QCM gold electrode and applied for selective uptake of IBP from sample solution by the aid of positive potential and its successive release by negative potential. The frequency shifts of QCM in uptake and release steps were monitored and used as sensor signal for IBP sorption/determination. In the biomedical samples, the frequency shift of release step exhibited more linear and interference free behavior. Several parameters like synthesis conditions, potential, time, pH of uptake and release and exchange anion type were explored to achieve the optimal sorption/determination conditions. The calibration graph was linear in the ranges of 1-10 and 10-100 mu mol L-1, the limit of detection was 0.05 timol L-1 and RSD% (n = 5) was lower than 3%. The proposed method was successfully applied for quantification of trace amounts of IBP in biomedical samples and validated by HPLC method. The CMIPIQCM sensor shows a good long-term stability and the sensor response drops 10% after 80 cycles of measurement in 8th week. (C) 2015 Elsevier B.V. All rights reserved.