Rapid diagnosis of multidrug resistance in cancer by electrochemical sensor based on carbon nanotubes-drug supramolecular nanocomposites

The multidrugresistance (MDR) in cancer is a major chemotherapy obstacle, rendering many currently available chemotherapeutic drugs ineffective. The aim of this study was to explore the new strategy to early diagnose the MDR by electrochemicalsensorbased on carbonnanotubes–drugsupramolecular interaction. The carbonnanotubes modified glassy carbon electrodes (CNTs/GCE) were directly immersed into the cells suspension of the sensitive leukemia cells K562 and/or its MDR cells K562/A02 to detect the response of the electrochemical probe of daunorubicin (DNR) residues after incubated with cells for 1 h. The fresh evidence from the electrochemical studies based on CNTs/GCE demonstrated that the homogeneous, label-free strategy could directly measure the function of cell membrane transporters in MDR cancer cells, identify the cell phenotype (sensitive or MDR). When the different ratios of the sensitive leukemia cells K562 and its MDR ones K562/A02 were applied as a model of MDR levels to simulate the MDR occurrence in cancer, the cathodic peak current showed good linear response to the fraction of MDR with a correlation coefficient of 0.995. Therefore, the MDR fraction can be easily predicted based on the calibration curve of the cathodic peak current versus the fraction of MDR. These results indicated that the sensing strategy could provide a powerful tool for assessment of MDR in cancer. The new electrochemicalsensorbased on carbonnanotubes–drugsupramolecularnanocomposites could represent promising approach in the rapiddiagnosis of MDR in cancer.