Design of a Quencher-Free Fluorescent Aptasensor for Ochratoxin A Detection in Red Wine Based on the Guanine-Quenching Ability

Biosensors

Amina Rhouati¹  Fathimath Abbas²  Shengnan Cui²  Bingbing Sun²  Xiaolin Chu²  Cheng Yang²  Yingying Sun²  Changying Xue³ 

[1] Bioengineering Laboratory, Higher National School of Biotechnology, Constantine 25100, Algeria;State Key Laboratory of Fine Chemicals, Department of Chemistry, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China;State Key Laboratory of Fine Chemicals, School of Bioengineering, Dalian University of Technology, Dalian 116024, China;

关键词: aptasensor;    quencher-free;    photo-induced electron transfer;    guanine-quenching fluorescence;    ochratoxin A;   

DOI  :  10.3390/bios12050297

来源: DOAJ

【 摘 要 】

This study describes a quencher-free fluorescent aptasensor for ochratoxin A (OTA) detection using the specific quenching ability of guanine for fluorescein (FAM) molecules based on photo-induced electron transfer (PIET). In this strategy, OTA is detected by monitoring the fluorescence change induced by the conformational change of the aptamer after target binding. A new shorter OTA aptamer compromising three guanine bases at the 5′ end was used in this study. This new aptamer, named G3-OTAapt1-FAM (F1), was labeled with FAM on the 3′ end as a fluorophore. In order to increase the binding affinity of the aptamer and OTA, G3-OTAapt2-FAM (F2) was designed; this added a pair of complementary bases at the end compared with F1. To prevent the strong self-quenching of F2, a complementary chain, A13, was added. Although the F1 aptasensor was simpler to implement, the sensitivity of the F2 aptasensor with A13 was better than that of F1. The proposed F1 and F2 sensors can detect OTA with a concentration as low as 0.69 nmol/L and 0.36 nmol/L, respectively.

【 授权许可】

Unknown