Layered molybdenum selenide stacking flower-like nanostructure coupled with guanine-rich DNA sequence for ultrasensitive ochratoxin A aptasensor application

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• 作者：Ke-Jing Huang ; ^{kejinghuang11@163.com" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Hong-Lei ShuaiAuthor Vitae ; Ying-Xu ChenAuthor Vitae
• 关键词：Molybdenum selenide nanoflowers ; Au nanoparticles ; Ochratoxin A ; Methylene blue ; Guanine-rich complementary DNA signal amplification
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：31 March 2016
• 年：2016
• 卷：225
• 期：Complete
• 页码：391-397
• 全文大小：2106 K

文摘

Sensitive detection of ochratoxin A (OTA) plays an important role in the field of food safety control. In this study, we are reporting for the first time an electrochemical biosensor which employs the integration of MoSe₂ nanoflowers, Au nanoparticles (AuNPs), aptamer and the guanine-rich complementary DNA sequence for the sensitive detection of OTA. MoSe₂ nanoflowers are prepared by a simple hydrothermal method and used as a promising sensing platform based on its large surface area. The methylene blue is used as a tracer and a guanine-rich complementary DNA sequence is designed to bind with the unbound OTA aptamer for signal amplification. The aptamer is immobilized on the AuNPs/MoSe₂ modified electrode surface through Au–S interaction. Since OTA can competitively bind with the aptamer due to their high affinity, the presence of OTA will induce the decrease of guanine-rich DNA on the electrode surface, in turn reduces the signal of methylene blue which can specifically adsorb to the guanine units of DNA. The proposed assay shows a good linear relationship within the range of 0.0001–1 nM with a detection limit of 0.08 pM for OTA. The developed biosensor has been applied to determine OTA concentration in wine samples.