Electrosynthesis and characterization of nanostructured polyquinone for use in detection and quantification of naturally occurring dsDNA

• Published in: Biosensors & bioelectronics Vol. 79; pp. 280 - 287
• Main Authors: Hernández, Loreto A., del Valle, María A., Armijo, Francisco
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15-05-2016
• Subjects: Anthraquinones - chemistry; Biosensing Techniques; Biosensors; Covalence; Deoxyribonucleic acid; DNA - isolation & purification; DNA quantification; Electrochemical DNA sensor; Electrochemical Techniques - methods; Electrodes; Homogeneity; Limit of Detection; Nanostructure; Nanostructures - chemistry; Nanowire electrosynthesis; Nanowires; Nucleic Acid Hybridization - methods; Poly(1-amino-9,10-anthraquinone); Polymer nanowires; Quinones - chemistry; Silicon Dioxide - chemistry; Strands; Nanowire electrosynthesis; DNA quantification; Polymer nanowires; Poly(1-amino-9,10-anthraquinone); Electrochemical DNA sensor
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2015.12.041

The detection of naturally occurring desoxyribonucleic acid (DNA) has become a subject of study by the projections that would generate to be able to sense the genetic material for the detection of future diseases. Bearing this in mind, to provide new measuring strategies, in the current work the preparation of a low-cost electrode, modified with poly(1-amino-9,10-anthraquinone) nanowires using a SiO2 template, is carried out; the assembly is next modified by covalently attaching ssDNA strands. It must be noted that all this is accomplished by using solely electrochemical techniques, according to methodology developed for this purpose. SEM images of the modified surface show high order and homogeneity in the distribution of modified nanowires over the electrode surface. In turn, after the hybridization with its complementary strand, the voltammetric responses enable corroborating the linear relationship between hybridization at different DNA concentrations and normalized current response, obtaining a limit of detection (LOD) 5.7·10−12gL−1 and limit of quantification (LOQ) 1.9·10−11gL−1. The working dynamic range is between 1.4·10−7 and 8.5·10−9gL−1 with a correlation coefficient 0.9998. The successful obtaining of the modified electrode allows concluding that the high order reached by the nanostructures, guides the subsequent single strand of DNA (ssDNA) covalent attachment, which after hybridization with its complementary strand brings about a considerable current increase. This result allows foreseeing a guaranteed breakthrough with regard to the use of the biosensor in real samples.
•P1AAQnanowires were electro-synthesized directly on a steel electrode.•Covalent modification of the P1AAQ nanowires with DNA, was corroborated by SEM images.•The analytic parameters for this new biosensor of DNA was: LOD of 5.7·10−12gL−1with a R2 of 0.9998.