Department of Chemistry, East China Normal University, 3663th Zhongshan Rd. (N), Shanghai 200062, PR China.
Biosens Bioelectron. 2011 Aug 15;26(12):4661-6. doi: 10.1016/j.bios.2011.04.017. Epub 2011 Jun 13.
A novel amplified electrochemical immunoassay based on ferrocene (Fc)-functionalized ZnO nanorods (NRs) was developed in the present work. The detection antibody ((d)Ab) and Fc were immobilized onto the surface of ZnO NRs, denoted as {(d)Ab-ZnO-Fc} bioconjugates. The amount of (d)Ab and Fc in the bioconjugates was investigated using the copper reduction/bicinchoninic acid reaction (BCA protein assay) and inductive coupled plasma-atomic emission spectroscopy (ICP-AES), respectively. Greatly amplified signal was achieved in the sandwich-type immunoassay when (d)Ab and Fc linked to ZnO NRs at a proper ratio. Using Escherichia coli (E. coli) as a model antigen, the designed immunoassay showed an excellent analytical performance, and exhibited a wide dynamic response range of E. coli concentration from 10(2) to 10(6)cfu/mL with a detection limit of 50 cfu/mL (S/N=3). By introducing a pre-enrichment step, the detection of 5 cfu/10 mL E. coli in hospital sewage water was realized. This proposed signal amplification strategy was promising and could be easily extended to monitor other biorecognition events.
本工作开发了一种基于二茂铁（Fc）功能化氧化锌纳米棒（NRs）的新型放大电化学免疫分析方法。检测抗体（（d）Ab）和 Fc 被固定在 ZnO NRs 表面，记为{(d)Ab-ZnO-Fc}生物缀合物。使用铜还原/双缩脲反应（BCA 蛋白测定法）和电感耦合等离子体原子发射光谱法（ICP-AES）分别研究了生物缀合物中（d）Ab 和 Fc 的量。当（d）Ab 和 Fc 以适当的比例连接到 ZnO NRs 时，在三明治型免疫测定中实现了大大放大的信号。使用大肠杆菌（E. coli）作为模型抗原，设计的免疫分析显示出优异的分析性能，表现出 E. coli 浓度从 10(2)到 10(6)cfu/mL 的宽动态响应范围，检测限为 50 cfu/mL（S/N=3）。通过引入预富集步骤，实现了对医院污水中 5 cfu/10 mL E. coli 的检测。这种提出的信号放大策略很有前途，可以很容易地扩展到监测其他生物识别事件。
