Amperometric DNA-Peroxidase Sensor for the Detection of Pharmaceutical Preparations

Abstract

Novel DNA-sensor with enzymatic amplification of the signal has beendeveloped on the base of glassy carbon electrode modified with ds-DNA and horseradishperoxidase (HRP). Phenothiazine dyes Methylene Blue and Methylene Green were used aselectrochemical markers for the detection of sulfonamide and anthracycline preparationsable to interact with DNA. The biosensor signal related to HRP oxidation of the markersdepends on the relation between their bonded and readily oxidized forms which depends onthe nature and concentration of pharmaceuticals. Sulfonamides diminish surfaceconcentration of MB accessible for HRP reaction whereas anthracyclines releaseintercalated marker and increase the signal. The DNA-HRP sensor developed makes itpossible to detect down to 0.002 nmol L-1 of sulfamethoxazole, 0.1 nmol L-1 of sulfadiazine,0.01 nmol L-1 of sulfamethazine, 0.1 nmol L-1 of sulfaguanine, 0.05 μmol L-1 of rubomycinand 0.08 μmol L-1 of doxorubicin.

Keywords

• DNA sensor
• affinity biosensor
• horseradish peroxidase
• sulfonamide determination
• anthracycline determination