Poly(Brilliant cresyl blue) as a perspective modifier for DNA sensors designed for DNA damage detection

The electrochemical characteristics of Brilliant cresyl blue and its polymeric form electrodeposited from the phosphate buffer on the screen-printed carbon electrodes (SPCE) were studied. It was shown by electrochemical quartz microbalance method that the frequency response gradually decreased with the number of electropolymerization cycles indicating the increasing mass of the polymeric product on the resonator surface. The poly(Brilliant cresyl blue) (PBCB) film was used along with native DNA from salmon sperm for the disposable DNA sensor assembly. The biocomponent immobilization strategies such as drying or incubation were tested to choose the optimal assembly protocol providing the greater response. The SPCE/PBCB/DNA sensor suggested was able to discriminate between various types of native and damaged DNA. Thermal denaturation, UV irradiation, ultrasound treatment and chemical oxidation by CuSO4 and H2O2 mixture were chosen as model DNA damaging agents. Finally, the sensor proposed was tested for the assessment of antioxidants protective effect of grapefruit, orange, lemon, bell pepper, red and yellow onion extracts. The pretreatment protocol was simple and can be widened for a greater range of the foods and beverages. The maximal protective effect was found for the lemon extract. The SPCE/PBCB/DNA sensor proposed can be applied in the ecological monitoring and food safety control.