Dual-ratiometric electrochemical sensor based on PAMAM/rGO/PGE for sensitive monitoring of anticancer drug imatinib in human samples

The development of a facile strategy for novel dual-ratiometric electrochemical sensing of anticancer drug imatinib in human samples is reported. For this purpose, a dendrimer/reduced graphene oxide modified pencil graphite electrode(PAMAM/rGO/PGE) was fabricated. This strategy referred to three types of substances with respective oxidation current peaks at different electric potentials, such as methylene blue (MB) at -0.26 V, ferrocene (Fc) at 0.15 V and imatinib at 0.84 V. In a conventional electrolyte solution of phosphate buffered saline (0.01 M, pH 4.5, containing 0.15 M of NaCl), MB and Fc as reference electroactive substances were added and their concentrations in electrolyte solution were fixed to 4 and 30 µM, respectively. Then, imatinib as the analyte was also added into the electrolyte solution to form a homogeneous solution through directly using a PAMAM/rGO/PGE as dual-signal sensing platform [1,2], differential pulse voltammetry curves of various electrolyte solutions containing three components of different concentrations were measured, with the increment of imatinib concentration from 0.01 to 5 µM. The ratiometric oxidation current peak intensities of imatinib to MB or Fc (Iimatinib/IMB or Iimatinib/IFc) almost linearly enhanced with the increase of imatinib concentration, together with good linear coefficients and low limits of detection (7.2 nM). The developed ratiometric electrochemical sensor of imatinib exhibited highly selective and sensitive responses to imatinib over potential interferences in real samples, accompanied by high detection recoveries.