The main problem of the electrochemical detection of purine nucleobases is connected with their direct electrooxidation at bare solid electrodes at high overvoltage. Therefore, there has been intensive research interest in the determination of Gua and Ade by means of different techniques based on novel bare electrodes or various chemically modified electrodes (CMEs). In particular, modification-free electrochemical approach for sensitive determination of purine DNA bases in biological samples using boron-doped diamond electrode has been described [15]. Numerous CMEs have been constructed for enhancing electrochemical signals of Gua and/or Ade by using single-walled carbon nanotubes (CNTs), multi-walled carbon nanotubes (MWCNTs) and nanostructured composites [16] and [17], including microwave-assisted prepared La(OH)3/CNTs [18], β-cyclodextrin/CNTs [19], CeO2 nanoparticles/MWCNTs [20], polythionine/gold nanoparticles/MWCNTs [21]. However, technologies of the majority of CMEs are complicated, time consuming and costly. Furthermore, the operating time of such sensors is usually rather short, which limits their application in automated systems.