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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (06): 687-692. 上一篇    下一篇

研究论文

高性能CdTe/CdS核壳型量子点的制备及应用于小麦面粉中呕吐毒素的荧光免疫检测研究

杨淑平，金鑫，郑佳，陶丽华，李在均*，，柯叶芳，刘俊康   

  1. (江南大学化学与材料工程学院 无锡 214122)
  • 投稿日期:2010-07-30 修回日期:2010-10-09 发布日期:2010-11-10
  • 通讯作者: 李在均 E-mail:zaijunli@263.net
  • 基金资助:

    国家自然科学基金项目;国家高技术计划“863”

Study on the Synthesis of High Performance CdTe/CdS Core/shell Quantum Dots and Its Application to Detect Deoxynivalenol in Wheat by Fluoroimmunoassay

YANG Shu-Ping, JIN Xin, ZHENG Jia, TAO Li-Hua, LI Zai-Jun, KE Ye-Fang, LIU Jun-Kang   

  1. (School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122)
  • Received:2010-07-30 Revised:2010-10-09 Published:2010-11-10

PDF

1551

被引次数

41

量子点荧光免疫法的广泛应用迫切需要提高量子点的发光强度和抗体的稳定性. 分别采用巯基乙酸和谷胱甘肽作稳定剂, 水相合成CdTe量子点, 再包覆CdS制备核壳型CdTe/CdS量子点. 以EDC/NHS作交联剂将CdTe/CdS量子点标记到呕吐毒素抗体上, 然后用牛血清蛋白封闭抗体. 研究发现, 谷胱甘肽稳定剂优于巯基乙酸. 与CdTe量子点相比, 谷胱甘肽修饰的CdTe/CdS量子点其荧光的强度和稳定性分别提高6倍和2倍以上. 谷胱甘肽碳链较长, 减少了量子点对抗体尤其是活性位点处的空间构型影响, 从而大大提高抗体的稳定性. 监测不同储藏时间(4 ℃)的CdTe/CdS量子点-抗体偶联复合物与呕吐毒素免疫反应前后荧光强度变化值, 结果显示抗体至少可以稳定7 d. 基于谷胱甘肽稳定的高性能CdTe/CdS量子点, 我们建立了一种新的呕吐毒素荧光免疫检测方法. 呕吐毒素浓度在0～0.9 ng•mL－1之间相对荧光强度呈线性关系, 相关系数(R2)为0.9992, 检出限是0.038 ng•mL－1. 方法的灵敏度高于文献报道的其它方法, 如GC-ECD, HPLC和HPLC-MS, 已成功应用于小麦面粉样品中痕量呕吐毒素的测定.

关键词: CdTe/CdS量子点, 呕吐毒素, 免疫检测, 谷胱甘肽, 小麦面粉

A wide use of quantum dots-based fluoroimmunoassay strongly requires to futher increase luminescent intensity of the quantum dots and stability of the antibody. To obtain CdTe/CdS core/shell type quantum dots, CdTe quantum dots was synthesized in aqueous medium and then wrapped with CdS shell well, in which thioglycolic acid or glutathione was used as a stabilizer. Then, the CdTe/CdS was covalently conjugated on the surface of antibody using EDC/NHS as crossing-linking reagent and the antibody was then blocked by bovine serum albumin. The experiments show that glutathione as stabilizer is better than thioglycolic acid. Compared with CdTe quantum dots, the luminescent intensity and stability of glutathione-stabilized CdTe/CdS core/shell quantum dots are higher 6 times and 2 times, respectively. The reason is that relatively long carbon chain of glutathione remarkably reduces effect of the CdTe/CdS quantum dots on the spatial confugation of antibody, especially for active sites regions. This results in enhancing stability of the antibody. In order to evaluate the stability of the antibody, the luminescent intensity change value of CdTe/CdS quantum dots-antibody complex deposited different time at 4 ℃ were measured before and after imcubated with deoxynivalenol. The results showed that the antibody can remain good stability at least 7 d. Based on the high performance of glutathione stabilized CdTe/CdS quantum dots, we developed a novel method for determination of deoxynivalenol by fluoroimmunoassay in the work. When concentration of deoxynivalenol is in the range from 0 to 0.9 ng•mL－1, its relative luminescent intensity has a good linear range relationship against the concentration of deoxynivalenol with a 0.9992 of the correlation coefficients (R2), and the detection limit was found to be 0.038 ng•mL－1, that is obviously better than other methods in literatures such as GC-ECD, HPLCand HPLC-MS. Proposed method has been successfully applied to deoxynivalenol analysis in real wheat.

Key words: CdTe/CdS quantum dots, deoxynivalenol, fluoroimmunoassay, glutathione, wheat flour