Electrochemical layer-by-layer modified imprinted sensor based on multi-walled carbon nanotubes and sol-gel materials for sensitive determination of thymidine

A novel electrochemical sol-gel imprinted sensor for sensitive and convenient determination of thymidine was developed. Thin film of molecularly imprinted sol-gel polymers with specific binding sites for thymidine was cast on carbon electrode by electrochemical deposition. Multi-walled carbon nanotubes (MWCNTs) were introduced for the enhancement of electronic transmission and sensitivity. The morphology and performance of the imprinted film was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV) and amperometric measurements (i-t) in detail. The results showed that the imprinted film exhibited high selectivity toward thymidine. The linear range is over the range from 2 to 22 mu mol L-1, and the linear regression equation for thymidine is I = 0.867C + 0.232 with the detection limit of 1.6 x 10(-9) mol L-1(S/N = 3). The imprinted sensor was successfully employed to detect thymidine in some zidovudine-tablet samples. (C) 2010 Elsevier B.V. All rights reserved.