Zhang Xiaohan, Zhuang Huisheng
School of Environment Science and Technology, Shanghai Jiao Tong University.
Anal Sci. 2017;33(12):1441-1446. doi: 10.2116/analsci.33.1441.
The extensive use of polybrominated diphenyl ethers (PBDEs) has resulted in its increasingly widespread presence. Especially the lower halogenated PBDEs accumulate to a greater degree than the higher halogenated PBDEs in house dust, sewage sludge, pets, or even humans. In the present work, we developed an ultrasensitive biotin-streptavidin-enhanced carbon nanotube amplification strategy for the immunodetection of PBDEs, in which single-walled carbon nanotubes were used to immobilize numerous streptavidin. Meanwhile, we used biotin conjugated horseradish peroxidase (B-HRP) and biotin conjugated Goat anti-rabbit (B-IgG) to link the HRP and IgG to CNTs by using a biotin-streptavidin system. The sensitivity of the streptavidin-biotin-IgG-CNTs-HRP bioconjugate was compared with a commercial HRP-labelled IgG by using indirect competitive ELISA. The limit of this proposed ELISA detection (IC) was 0.0059 ng/mL, showing a 20-time lower detection limit over the commercial one (IC = 0.1193 ng/mL). Finally, we applied the assay to the detection of PBDEs in dust samples. The results were consistent with those using GC-ECD, which confirmed that the proposed amplification strategy was accurate and receptive. This proposed biotin-streptavidin-enhanced carbon nanotube amplification strategy would be useful for ultrasensitive immunodetection in environmental studies.
多溴二苯醚（PBDEs）的广泛使用导致其存在日益广泛。尤其是低卤代多溴二苯醚比高卤代多溴二苯醚在室内灰尘、污水污泥、宠物甚至人类中积累程度更高。在本研究中，我们开发了一种用于多溴二苯醚免疫检测的超灵敏生物素-链霉亲和素增强碳纳米管放大策略，其中单壁碳纳米管用于固定大量链霉亲和素。同时，我们使用生物素偶联辣根过氧化物酶（B-HRP）和生物素偶联山羊抗兔抗体（B-IgG），通过生物素-链霉亲和素系统将HRP和IgG连接到碳纳米管上。通过间接竞争ELISA比较了链霉亲和素-生物素-IgG-碳纳米管-HRP生物共轭物与市售HRP标记IgG的灵敏度。该ELISA检测方法的检测限（IC）为0.0059 ng/mL，比市售方法（IC = 0.1193 ng/mL）的检测限低20倍。最后，我们将该方法应用于灰尘样品中多溴二苯醚的检测。结果与使用气相色谱-电子捕获检测器（GC-ECD）的结果一致，这证实了所提出的放大策略准确且灵敏。所提出的生物素-链霉亲和素增强碳纳米管放大策略将有助于环境研究中的超灵敏免疫检测。
