Voltammetric responses at modified electrodes and aggregation effects of two anticancer molecules: irinotecan and sunitinib

The voltammetric responses of two anticancer molecules irinotecan (ITC) and sunitinib (SUN) were investigated at glassy carbon (GC) and indium tin oxide (ITO) electrodes bare or modified with carbon nanotubes (NTs), NT-Nafion composites (NafionNTs) and poly(3,4-ethylenedioxy-thiophene) (PEDOT). Bare GC electrodes revealed to be the most suitable for the detection of drugs at low concentration levels. Differential pulse voltammetry (DPV) analyses showed that the responses of the anticancer molecules are affected by the formation of aggregates. In particular, aggregation of SUN results in the formation of H-aggregates. DPV analysis extended to human plasma samples revealed the drugs in micromolar concentrations with good reproducibility.