An Electrochemical DNA Sensor for Doxorubicin Based on a Polyelectrolyte Complex and Aminated Thiacalix[4]Arene

An impedimetric DNA sensor is developed for the highly sensitive determination of doxorubicin; the signal is charge transfer resistance recorded by electrochemical impedance spectroscopy using a glassy carbon electrode modified by electropolymerized Neutral Red or polyaniline and polyelectrolyte complexes including DNA. The nature of the polymer layer and the composition of the polyelectrolyte complex affect the sensitivity of the determination of doxorubicin. The role of a macrocycle capable of shielding the DNA negative charge and interacting with cationic centers of the substrate is shown. With an optimal composition of polyelectrolytes, the DNA sensor ensures the determination of down to 0.1 nM of doxorubicin.