Electrochemical Label-free and Reagentless Genosensor Based on an Ion Barrier Switch-off System for DNA Sequence-Specific Detection of the Avian Influenza Virus

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• 作者：Katarzyna Kurz膮tkowska ; Agnieszka Sirko ; W艂odzimierz Zag贸rski-Ostoja ; Wim Dehaen ; Hanna Radecka ; Jerzy Radecki
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：October 6, 2015
• 年：2015
• 卷：87
• 期：19
• 页码：9702-9709
• 全文大小：446K
• ISSN：1520-6882

文摘

This paper concerns the development of genosensors based on redox-active monolayers incorporating (dipyrromethene)₂Cu(II) and (dipyrromethene)₂Co(II) complexes formed step by step on a gold electrode surface. They were applied for electrochemical determination of oligonucleotide sequences related to avian influenza virus (AIV) type H5N1. A 20-mer probe (NH₂-NC3) was covalently attached to the gold electrode surface via a reaction performed in the presence of ethyl(dimethylaminopropyl)carbodiimide / N-hydroxysuccinimide (EDC/NHS) between the amine group present in the probe and carboxylic groups present on the surface of the redox-active layer. Each modification step has been controlled with Osteryoung square-wave voltammetry. The genosensor incorporating the (dipyrromethene)₂Cu(II) complex was able to detect a fully complementary single-stranded DNA target with a detection limit of 1.39 pM. A linear dynamic range was observed from 1 to 10 pM. This genosensor displays good discrimination between three single-stranded DNA targets studied: fully complementary, partially complementary (with only six complementary bases), and totally noncomplementary to the probe. When the (dipyrromethene)₂Co(II) complex was applied, a detection limit of 1.28 pM for the fully complementary target was obtained. However, this genosensor was not able to discriminate partially complementary and totally noncomplementary oligonucleotide sequences to the probe. Electrochemical measurements, using both types of genosensors in the presence of different supporting electrolytes, were performed in order to elaborate a new mechanism of analytical signal generation based on an ion barrier 鈥渟witch-off鈥?system.