Homogenous detection of fumonisin B₁ with a molecular beacon based on fluorescence resonance energy transfer between NaYF₄: Yb, Ho upconversion nanoparticles and gold nanoparticles

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• 作者：Shijia Wu ; Nuo Duan ; Xiangli Li ; Guiliang Tan ; Xiaoyuan Ma ; Yu Xia ; Zhouping Wang ; Hongxin Wang
• 关键词：Fumonisin B1 ; NaYF4 ; Yb ; Ho upconversion nanoparticles ; Gold nanoparticles ; Fluorescence resonance energy transfer ; Molecular beacons
• 刊名：Talanta
• 出版年：15 November, 2013
• 年：2013
• 卷：116
• 期：Complete
• 页码：611-618
• 全文大小：1611 K

文摘

In this work, we presented a new aptasensor for fumonisin B₁ (FB₁) based on fluorescence resonance energy transfer (FRET) between NaYF₄: Yb, Ho upconversion fluorescent nanoparticles (UCNPs) and gold nanoparticles (AuNPs). The quenchers (AuNPs) were attached to the 5鈥?end of the molecular beacon (MB), and the donors (UCNPs) were attached to the 3鈥?end of the MB. In the absence of target DNA (DNA complementary to FB₁ aptamers), the energy donors and acceptors were placed in close proximity, leading to quenching of the fluorescence of the UCNPs. Due to the combination of FB₁ and FB₁-specific aptamers, this caused some complementary DNA dissociating from the magnetic nanoparticles (MNPs). In the presence of the complementary DNA, the MBs underwent spontaneous conformational change and caused the UCNPs and AuNPs to detach from each other, resulting in restoration of the upconversion fluorescence. Therefore, the fluorescence of UCNPs was restored in a FB₁ concentration-dependent manner, which was the basis of the FB₁ quantification. The aptasensors showed a linear relationship from 0.01 to 100 ng mL^鈭? for FB₁ with a detection limit of 0.01 ng mL^鈭? in an aqueous buffer. As a practical application, the aptasensor was used to monitor FB₁ levels in naturally contaminated maize samples. The results were consistent with that of a classic ELISA method, indicating that the UCNPs-FRET aptasensor, which benefited from the near infrared excitation of NaYF₄: Yb, Ho UCNPs, was effective for directly sensing FB₁ in foodstuff samples without optical interference. This work also created the opportunity to develop aptasensors for other targets using this FRET system.