Electrochemical genosensor based on disc and screen printed goldelectrodes for detection of specific DNA and RNA sequences derivedfrom Avian Influenza Virus H5N1

Abstract

tThe genosensors based on thiolated ssDNA probe deposited on the two types of gold electrodes: screen-printed (miniaturized) and disc electrodes destined for determination of specific sequences of DNA andRNA derived from Avian Influenza Virus H5N1 have been proposed. The working principle of genosensor isbased on the ion-channel mechanism. The analytical signals generated upon hybridization processes wererecorded using electrochemical technique – Osteryoung square wave voltammetry in the presence of aredox active marker [Fe(CN)6]3−/4−in the sample solution. The miniaturized genosensor based on screenprinted gold electrodes was able to detect the 20-mer complementary DNA oligonucleotide sequence aswell as ∼280-mer RNA sequences containing the complementary 20-mer sequence in various positions:at 3�-terminus, at 5�-terminus and in the middle of the RNA transcript at the 1 pM concentration. Themeasuring systems were selective. Non-complementary 20-mer oligonucleotide sequence as well asRNA transcript without complementary region generated weak response. The RNA transcripts were alsotested with gold disc electrodes modified in the same manner. This device was able to detect ∼280-mer RNA sequences, but at higher concentration of 10 pM. The good discrimination of the position ofcomplementary part in the ∼280-mer RNA sequences was observed with using both types of modifiedelectrodes.