Ultrasensitive aflatoxin B1 assay based on FRET from aptamer labelled fluorescent polymer dots to silver nanoparticles labeled with complementary DNA
Ultrasensitive aflatoxin B1 assay based on FRET from aptamer labelled fluorescent polymer dots to silver nanoparticles labeled with complementary DNA
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DOI：
10.1007/s00604-017-2508-5
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发表时间：
2017-12-01
影响因子：
5.7
通讯作者：
Shamsipur, Mojtaba
中科院分区：
文献类型：
--
作者：
Nasirian, Vahid;Chabok, Ammar;Shamsipur, Mojtaba
作者描述了一种基于荧光共振能量转移（FRET）的纳米生物探针通过关-开信号过程选择性检测黄曲霉毒素B1（AFB 1）的新方法。将针对AFB 1的氨基修饰的适体缀合至荧光聚合物点，所述荧光聚合物点含有聚[（9，9-二辛基芴基-2，7-二基）-co-（1，4-苯并噻二唑）]作为荧光团。将互补DNA（cDNA）缀合至充当FRET受体的银纳米颗粒（cDNA-AgNP）。在溶液中混合，在没有AFB 1的情况下，适体和其cDNA杂交形成（适体-cDNA）。这使得聚合物点紧密接近AgNP，并且由于聚合物点的发射和AgNP的吸收之间的光谱重叠而导致从供体到受体的FRET。从而关闭聚合物点探针的荧光。然而，在存在AFB 1的情况下，对AFB 1具有高亲和力的适体将从cDNA-AgNP聚集体中释放，这导致荧光恢复（“开启”状态）。聚合物点的黄色荧光在538 nm处测量最佳，在5 pg.mL（-1）至1.0 ng.mL（-1）AFB 1浓度范围内线性增加，检测限为0.3 pg.mL（-1）。该方法已成功地应用于检测（加标）小麦粉中的黄曲霉毒素B1，结果被认为是在令人满意的协议，通过酶联免疫吸附试验得到的。
The authors describe a new method for the selective detection of aflatoxin B1 (AFB1) by an off-on signaling procedure in a fluorescence resonance energy transfer (FRET)based nanobioprobe. An amino-modified aptamer against AFB1 was conjugated to fluorescent polymer dots, containing poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzothiadiazole)] as the fluorophore. Complementary DNA (cDNA) was conjugated to silver nanoparticles (cDNA-AgNPs) which act as FRET acceptors. Mixed in solution, in the absence of AFB1, the aptamer and its cDNA hybridize to form (aptamer-cDNA). This brings the polymer dots into close proximity of the AgNPs and result in FRET from the donor to the acceptor due to spectral overlap between the emission of the polymer dots and the absorption of the AgNPs. The fluorescence of the polymer dots probe is thereby switched off. However, in the presence of AFB1, the aptamer with high affinity for AFB1 will be released from the cDNA-AgNP aggregate, which results in recovery of fluorescence (Bswitch on" state). The yellow fluorescence of the polymer dots, best measured at 538 nm, increases linearly in the 5 pg.mL(-1) to 1.0 ng.mL(-1) AFB1 concentration range, with a 0.3 pg.mL(-1) detection limit. The assay was successfully applied to the detection of AFB1 in (spiked) wheat flour, and the results were found to be in satisfactory agreement with those obtained by an enzyme-linked immunosorbent assay.