Electrochemical DNC-sensor for doxorubicin based on composites of graphene oxide, electropolymerized Azur A and Methylene green

A voltammetric DNA sensor for the determination of doxorubicin was developed, the signal of which is the change in the current of the redox mediator Methylene green, recorded by cyclic voltammetry on a glass-carbon electrode modified with electrochemically reduced graphene oxide, electropolymerized Azur A and DNA saturated with Methylene green. The influence of the nature of the polymer layer and the redox mediator used on the sensitivity of doxorubicin determination was determined. At optimal composition of the surface layer the DNA-sensor allows to determine up to 0.01 pM of doxorubicin. The sensor was tested on a number of model (artificial urine, Ringer-Locke’s solution, bovine serum albumin solution) and biological samples (saliva, urine) containing doxorubicin.