Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China; Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education), School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
Biosens Bioelectron. 2015 Jun 15;68:586-592. doi: 10.1016/j.bios.2015.01.051. Epub 2015 Jan 22.
Bifunctional magnetic nanobeads (bi-MBs) were fabricated by co-immobilizing target recognition molecules and signal molecules on a magnetic nanobead surface, which were used as both separation and enrichment carriers and signal carriers. The bi-MBs could capture and separate avian influenza A (H7N9) virus (H7N9 AIV) from complex samples efficiently based on the specific reaction between antigen-antibody and their good magnetic response, which simplified sample pretreatment and saved the detection time. Taking advantages of their high surface to volume ratio and rich surface functional groups, multiple alkaline phosphatase (ALP) signal molecules were tethered on the surface of bi-MBs which greatly amplified the detection signal. As an efficient signal amplification strategy, enzyme-induced metallization had been integrated with bi-MBs and anodic stripping voltammetry to construct an ultrasensitive electrochemical immunosensor for H7N9 AIV detection. Under the optimal conditions, the introduction of bi-MBs could amplify the detection signal in about four times compared with the same immunoassay without MBs, and the method showed a wide linear range of 0.01-20 ng/mL with a detection limit of 6.8 pg/mL. The electrochemical immunosensor provides a simple and reliable platform with high sensitivity and selectivity which shows great potential in early diagnosis of diseases.
双功能磁性纳米珠（bi-MBs）通过将靶标识别分子和信号分子共固定在磁性纳米珠表面上而制备，其既可用作分离和富集载体，也可用作信号载体。bi-MBs 能够基于抗原-抗体之间的特异性反应及其良好的磁响应，从复杂样品中高效捕获和分离甲型流感病毒（H7N9）（H7N9 AIV），从而简化了样品预处理并节省了检测时间。利用其高的比表面积与丰富的表面官能团，将多个碱性磷酸酶（ALP）信号分子键合到 bi-MBs 表面，从而极大地放大了检测信号。作为一种有效的信号放大策略，酶诱导的金属化已与 bi-MBs 和阳极溶出伏安法集成，以构建用于 H7N9 AIV 检测的超灵敏电化学免疫传感器。在最佳条件下，与没有 MBs 的相同免疫测定相比，bi-MBs 的引入可将检测信号放大约 4 倍，并且该方法显示出 0.01-20ng/mL 的宽线性范围，检测限为 6.8pg/mL。该电化学免疫传感器提供了一种具有高灵敏度和选择性的简单可靠平台，在疾病的早期诊断中具有巨大的应用潜力。
