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Title Preparation of an electrochemical PNA biosensor for detection of target DNA sequence and single nucleotide mutation on p53 tumor suppressor gene corresponding oligonucleotide
Type JournalPaper
Keywords Peptide nucleic acid, Self-assembled monolayer, Methylene blue, p53 Oligonucleotide
Abstract Development of an electrochemical biosensor based on peptide nucleic acid (PNA) probe for detection of target DNA sequence and single nucleotide mutation in p53 tumor suppressor gene corresponding oligonucleotide using methylene blue (MB) as an electrochemical indicator is described. The interaction between MB and short sequence of p53, one of the most important tumor suppressor genes due to its dysfunction in the majority of human cancers, was studied by differential pulse voltammety (DPV). Probe modified electrode was prepared by self-assembled monolayer (SAM) formation of thiolated PNA molecules on the surface of gold electrode (GE). The hybridization of PNA probe with target DNA was performed in solution to form PNA–DNA hybrid on the surface of the GE. A significant increase in the reduction signal of MB was observed upon hybridization of the probe with the complementary DNA. The selectivity of the biosensor was studied using noncomplementary oligonucleotides. Furthermore, our results confirmed the ability of the sensor to detect single base mismatch in the sample oligonucleotide. The influence of probe concentration on the effective discrimination against noncomplementary sequence and point mutation was also investigated. Diagnostic performance of the biosensor is described and the detection limit is found 6.82 × 10 −10 M. The electrochemical impedance spectroscopy was also employed to further investigate the sensor function
Researchers Mohammad Saeid Hejazi (Fifth Researcher), Ezat Hamidi-Asl (Fourth Researcher), Seyed Mahdi Golabi (Third Researcher), Reza Ojani (Second Researcher), Jahan Bakhsh Raoof (First Researcher)