School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Anal Chim Acta. 2019 Jan 24;1047:163-171. doi: 10.1016/j.aca.2018.10.002. Epub 2018 Oct 5.
Development of sensitive methods for trace aflatoxin B1 (AFB1) determination is of great significance due to its high toxicity and carcinogenicity. Herein, 3-mercaptopropionic acid (MPA)-capped ternary CdZnTe quantum dots (QDs) have been prepared via a simple hydrothermal route. We found that they exhibited enhanced intensity when benchmarked against their binary counterpart CdTe QDs. On this basis, a target-driven switch-on fluorescence aptasensor for trace AFB1 determination has been developed by employing the fluorescence resonance energy transfer (FRET) between the CdZnTe QDs and Au nanoparticles (AuNPs) pair. In the detection diagram, amino group-functionalized aptamers against AFB1 were firstly labelled with the CdZnTe QDs donors coated on silica nanospheres while the AuNPs acceptors were bioconjugated with the thiol group-modified complementary DNA (cDNA) of aptamer. By taking advantage of the DNA hybridization of aptamer and cDNA, the CdZnTe QDs (energy donor) and AuNPs (energy acceptor) were brought into close proximity, thereby leading to the occurrence of FRET during the aptasensor fabrication. When the aptasensor was incubated with AFB1, the specific binding between aptamer and target resulted in the detachment of AuNPs acceptors. This behavior would disturb the FRET process and led to the subsequent fluorescence recovery of CdZnTe QDs. Such designed aptasensor showed an increased fluorescence recovery upon the increasing concentration of AFB1 over a broad range of 50 pg mL - 100 ng mL and succeeded in spiked peanut samples. The proposed aptasensor is separation-free and easy-to-use, which might open up new possibilities in aptasensor fabrication by employing the novel CdZnTe QDs-AuNPs pair.
由于其高毒性和致癌性，开发灵敏的方法来测定痕量黄曲霉毒素 B1（AFB1）具有重要意义。在此，通过简单的水热法制备了巯基丙酸（MPA）封端的三元 CdZnTe 量子点（QDs）。我们发现，与二元 CdTe QDs 相比，它们的强度增强了。在此基础上，通过 CdZnTe QDs 和 Au 纳米粒子（AuNPs）之间的荧光共振能量转移（FRET），开发了一种基于靶标驱动的荧光适配体传感器，用于痕量 AFB1 的测定。在检测图中，首先将针对 AFB1 的氨基功能化适配体标记在涂有 CdZnTe QDs 的硅纳米球上，而 AuNPs 则通过与适配体的硫醇修饰互补 DNA（cDNA）进行生物共轭。利用适配体和 cDNA 的 DNA 杂交，将 CdZnTe QDs（能量供体）和 AuNPs（能量受体）紧密结合，从而在适配体传感器的制备过程中发生 FRET。当将适配体传感器与 AFB1 孵育时，适配体与靶标的特异性结合导致 AuNPs 受体的脱离。这种行为会干扰 FRET 过程，并导致 CdZnTe QDs 的随后荧光恢复。该设计的适配体传感器在 AFB1 浓度在 50 pg mL-1 至 100 ng mL-1 的较宽范围内增加时表现出荧光恢复增加，并成功应用于加标花生样品中。该提出的适配体传感器无需分离且易于使用，这可能通过采用新型 CdZnTe QDs-AuNPs 对在适配体传感器制造方面开辟新的可能性。
