Electrochemical Detection of Abasic Site‐Containing DNA

Abstract

A simple and rapid approach for detecting apurinic (AP) sites in DNA, based on direct stripping chronopotentiometric measurements of the adenine and guanine nucleobases at a graphite electrode is described. Tetrahydrofuranyl residues, lacking a nucleobase moiety, were utilized for designing the AP sites and were incorporated in 19-mer oligonucleotides. The change of adenine-to-guanine response ratio (A/G) in one-, two-or three-substituted adenosine residues for stable analogs of AP sites was exploited for electrochemical measurements of the adenine loss. The resulting A/G response ratio decreases linearly upon increasing the number of AP sites in the oligonucleotides; the values of A/G electrochemical signals were slightly enhanced when compared to the actual purine content. HPLC analysis of the released nucleobases confirmed that the sulfuric acid-induced oligonucleotide cleavage provides complete apurination and dissolution of the released nucleobases in aqueous solution. Additional experiments with mixtures of free nucleobases and purine nucleosides reveal that the larger A/G ratio observed in the electrochemical analysis of AP-site-containing oligomers is attributed to the influence of the acid and/or thermal decomposition products (particularly the sugar fragments). This study represents the first step in developing a simple and direct electrochemical assay of AP sites in single-stranded DNA.

Functionalized Solid Electrodes for Electrochemical Biosensing of Purine Nucleobases and Their Analogues: A Review

“…A simple and rapid approach for detecting apurinic sites in DNA, based on direct stripping chronopotentiometric measurements of Ade and Gua nucleobases at a PeGE was described [ 35 ]. Experiments with mixtures of free nucleobases and purine nucleosides revealed that the larger A/G ratio observed in the electrochemical analysis of apurinic site-containing oligomers is attributed to the influence of the acid and/or thermal decomposition products.…”

Redmond Red as a Redox Probe for the DNA-Mediated Detection of Abasic Sites

“…More recently, studies have reported the detection of these damaged sites specifically in synthetic oligonucleotides using chronopotentiometric and square wave voltammetric techniques (32-35). These systems, however, possess intrinsic limitations that prevent them from serving as practical diagnostics.…”

“…Early work first demonstrated the sensitivity of electrochemical techniques to the presence of abasic sites resulting from depurination in chromosomal DNA: differential poloragraphic responses were observed for nondenatured DNA versus the apurinic form − . More recently, studies have reported the detection of these damaged sites specifically in synthetic oligonucleotides using chronopotentiometric and square wave voltammetric techniques − . These systems, however, possess intrinsic limitations that prevent them from serving as practical diagnostics.…”

Magnetic beads-based electrochemiluminescence immunosensor for determination of cancer markers using quantum dot functionalized PtRu alloys as labels

“…The electrochemical immunosensor that utilizes integrating enzyme assisted signal amplification processes, and incorporates nanomaterials to increase loading of tags has been demonstrated to be one of the most practical solutions due to its capability to conduct highly molecular specific measurements. [25][26][27] Among the nanomaterials used, nanoporous structures have attracted considerable attention due to their promising potential in the use of catalysis, 28 lithium ion batteries, 29 photodynamic therapy 30 and electrical conduction. 31 Owing to their bicontinuous nanoscale skeletons and interconnected hollow channels, they are favorable for easy mass transport and high electron conductivity.…”