Introduction of an Electrochemical Genosensor for Detection of P53 Gene Via Sandwich Hybridization Method

Abstract

Sequence-specific detection of DNA provides the basis for detection of a wide variety of infectious and inherent disease. Electrochemical hybridization biosensors for the detection of DNA sequences reduce the assay time and simplify medical analysis. In this work, we introduce a biosensor for investigation of DNA hybridization related to p53 gene corresponding oligonucleotide. Due to the high importance of p53 gene detection in various fields of medicine and biology, we attempted to prepare a rapid and sensitive enzyme-linked electrochemical genosensor using screen printed electrodes (SPE). Hybridization was performed on streptavidin coated paramagnetic micro-beads functionalized with a biotinylated capture probe. The complementary sequence was then recognized via sandwich hybridization with a capture probe and a biotinylated signaling probe. After labeling the biotinylated hybrid with a streptavidin–alkaline phosphatase conjugate, the particles were introduced onto a disposable SPE. The modified particles were trapped with a magnet onto the sensor surface. Then a known volume of a solution containing the enzymatic substrate, α-naphthyl phosphate, was added on the SPEs surfaces. The oxidation signal of the enzymatically produced α-naphthol was investigated by differential pulse voltammety. The genosensor response varied linearly with the oligonucleptide target concentration between 0.05 nM and 2.0 nM. The estimated detection limit was 0.03 nM.