A carbon nanotubes/graphite paste electrode impregnated with stavudine-imprinted polymer as a stavudine selective sensor

A potentiometric sensor based on carbon paste electrode impregnated concurrently with molecularly imprinted polymer (MIP) and multi-walled carbon nanotubes (MWCNTs) was fabricated and used to measure stavudine (STV), currently applied as a drug in the treatment of human immuno-deficiency virus (HIV) infection. To synthesize the MIP, methacrylic acid (or acryl amide) and ethylene glycol dimethacrylate were utilized as functional monomer and cross-linker, respectively. The kind of the functional monomer had decisive influence on the response of the MIP-based electrode to target molecule of STV. MWCNTs had positive effect on both sensitivity and detection range of the electrode. The electrode response behavior (Nernstian behavior) was shown to be affected by homoconjugation of STV molecules in the imprinting process. The proposed sensor exhibited Nernstian slope of 27.9 mV per decade for stavudine over a wide concentration range of 1.0 x 10(-6) to 1.0 x 10(-1) mol L-1, with a detection limit of 5.0 x 10(-7) mol L-1. The sensor was used for STV determination in pharmaceutical samples.