State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Talanta. 2016 Sep 1;158:246-253. doi: 10.1016/j.talanta.2016.05.063. Epub 2016 May 26.
A multiplexed, sensitive and specific detection method is highly desirable for the simultaneous detection of several pathogenic bacteria and bio-toxins. In our previous work, multicolor upconversion nanoparticles (UCNPs) via doping with various rare-earth ions to obtain well-separated emission peaks by means of a solvothermal method were synthesized and were successfully applied as luminescence labels in the detection of three pathogenic bacteria. One of the basic achievements of our group has been to establish that the key to increasing the number of simultaneous detection components is the preparation of more UCNPs, the emission peaks of which can be distinguished from each other. According to this vision, NaYF4:Yb0.2, Tm0.02 UCNPs were obtained via a thermal-decomposition protocol, which has a main near-infrared (NIR) UC emission at 804nm under 980nm excitation. The emission peak at 804nm was well-separated from the emission peaks of UCNPs we have reported at 477nm, 542nm, and 660nm. It means both the excitation and the emission of NaYF4:Yb0.2, Tm0.02 UCNPs are located in the NIR spectral range (NIR-to-NIR UC emission), the so-called biological window. This result establishes the basis of achieving simultaneous detection of four components. To confirm the analytical performance of this NaYF4:Yb0.2, Tm0.02 UCNPs, a novel near-infrared magnetic aptasensor for the detection of Ochratoxin A (OTA) was developed using the OTA aptamer-conjugated near-infrared upconversion nanoparticles (apt-UCNPs) and the complementary oligonucleotide-modified magnetic nanoparticles (cDNA-MNPs). The apt-UCNPs and cDNA-MNPs were hybridized to form a poly-network structure of MNP-UCNP nanocomposites. When the target OTA was introduced, the aptamer combined with the priority target and the cDNA-MNPs were replaced. The proposed method achieved a linear range between 0.01 and 100ngmL(-1), with a detection limit as low as 0.005ngmL(-1). Then, we successfully applied this method to measure Ochratoxin A (OTA) in beer samples and the results demonstrated that the method possessed a high sensitivity and good selectivity for the determination of OTA and thus is applicable to the determination of OTA in beer samples. This satisfying result shows that the NaYF4:Yb0.2, Tm0.02 UCNPs we synthesized has a great prospect in multiplexed simultaneous detection.
一种多路复用、敏感且特异的检测方法对于同时检测多种病原体和生物毒素非常理想。在我们之前的工作中，通过使用溶剂热法掺杂各种稀土离子来合成具有良好分离发射峰的多色上转换纳米粒子（UCNPs），并成功地将其用作三种病原体检测的荧光标记物。我们小组的一项基本成果是，增加同时检测组件数量的关键是制备更多的 UCNPs，这些 UCNPs 的发射峰可以彼此区分。根据这一设想，通过热分解法获得了 NaYF4:Yb0.2，Tm0.02 UCNPs，在 980nm 激发下，其具有主要的近红外（NIR）上转换发射峰在 804nm。804nm 的发射峰与我们之前在 477nm、542nm 和 660nm 处报道的 UCNPs 的发射峰很好地分离。这意味着 NaYF4:Yb0.2，Tm0.02 UCNPs 的激发和发射都位于近红外光谱范围内（近红外到近红外上转换发射），即所谓的生物窗口。这一结果为实现同时检测四个组件奠定了基础。为了证实这种 NaYF4:Yb0.2，Tm0.02 UCNPs 的分析性能，我们开发了一种新型近红外磁性适体传感器，用于检测赭曲霉毒素 A（OTA），该传感器使用 OTA 适体偶联的近红外上转换纳米粒子（apt-UCNPs）和互补寡核苷酸修饰的磁性纳米粒子（cDNA-MNPs）。apt-UCNPs 和 cDNA-MNPs 杂交形成 MNPUCNP 纳米复合材料的多网络结构。当引入目标 OTA 时，适体与优先目标结合，并用 cDNA-MNPs 取代。该方法在 0.01 至 100ngmL(-1) 之间呈现线性范围，检测限低至 0.005ngmL(-1)。然后，我们成功地将该方法应用于测量啤酒样品中的赭曲霉毒素 A（OTA），结果表明该方法对 OTA 的测定具有很高的灵敏度和良好的选择性，因此适用于啤酒样品中 OTA 的测定。令人满意的结果表明，我们合成的 NaYF4:Yb0.2，Tm0.02 UCNPs 在多路复用同时检测方面具有广阔的前景。
