用于黄曲霉素B1检测的表面增强型荧光光学传感器

黄曲霉素B1(aflatoxin B1,AFB1)是一种常见于农作物中的真菌毒素,是所有真菌霉素中毒性最强且具有致癌性。因此,快速、有效地检测出食品中AFB1对于食品安全来说具有重要意义。设计了一种基于表面增强荧光(surface-enhanced fluorescence,SEF)技术的光学芯片用于AFB1灵敏检测。该光学芯片以纳米多孔金(nanoporous gold,NPG)作为荧光增强基底,通过在其表面先后组装适体SH-DNA2和互补适体Cy5-DNA1构建针对AFB1的功能芯片。该芯片利用AFB1和Cy5-DNA1与SH-DNA2之间竞争结合,释放Cy5-DNA1引发来自Cy5荧光信号的衰减,通过监测Cy5的荧光强度的变化实现对AFB1的检测,检测极限可达到10^?7μg/L且线性动态范围有4个量级。

A surface-enhanced fluorescent sensor for sensitive detection of aflatoxin B1

Aflatoxin B1(AFB1)is a fungal toxin common in crops and it is the most toxic of all mycotoxins which can cause cancer.Thus,quick and effective detection of AFB1 is important for food security.Here,a simple and sensitive optical sensor based on surface-enhanced fluorescence(SEF)technique was designed to detect AFB1.We used nanoporous gold(NPG)as the substrate.The AFB1 aptamer(Cy5-DNA1)and AFB1 complementary aptamer(SH-DNA2)were successively assembled on the surface of NPG to form the optical sensor for AFB1.Competitive binding between AFB1 and Cy5-DNA1 released Cy5-DNA1 from NPG,leading fluorescence intensity of Cy5 to fall.AFB1 was detected by monitoring the variation of the fluorescnece intensity of Cy5 and the final detection limit was 10^?7μg/L with a linear dynamic range 4 orders of magnitude.