传感器类型
综述或非传感器论文
检测对象
抗原(antigen)、病毒(virus,如单纯疱疹病毒 HSV)、噬菌体(phage)、微球(microsphere,生物素-链霉亲和素体系);样品基质:复杂血清/血液、缓冲液
检测原理
键断裂免疫传感器将抗体、适配体或链霉亲和素等识别元件固定于 QCM 或 SAW 压电表面。目标抗原/病毒/微球进入样品后,与识别元件形成特异性键,同时复杂基质中的其他分子形成非特异性键。通过逐步提高驱动功率,压电表面在共振频率下产生较大振幅,对结合物施加周期性机械力。低亲和力的非特异键先断裂,高亲和力的特异键在更高力下断裂。键断裂事件引起表面质量突变并产生宽带电子噪声,噪声峰高和出现位置反映结合物数量与键强度;共振频率变化则按 Sauerbrey 或 Kanazawa-Gordon 关系反映表面质量。因此靶标浓度越高,结合物越多,断裂噪声峰越强、频率变化越大,从而实现无标记、可区分特异/非特异的检测。
检测灵敏度
原文未报告 LOD、线性范围、灵敏度斜率或相关系数。
效应效果
作者主张键断裂法快速、简单、无标记且无需前处理,可在血液等复杂血清中区分特异与非特异结合,既能定性检测靶标,也可定量估计浓度,目标周转时间可短于 1 h。已有 QCM 实验成功记录微球、生物素-链霉亲和素、麦芽糖结合噬菌体和单纯疱疹病毒等目标;单键断裂力约 2–200 pN,生物素-链霉亲和素约 160 pN,硫-金键约 1.4 nN,微球断裂时每球约 10 nN。SAW 也证实键断裂噪声原理,但一致性不如 QCM。未报告 RSD、回收率或与 ELISA/HPLC/qPCR 的直接对比。挑战包括复杂溶液批间差异、高灵敏度、低干扰不足;SAW 高功率下可出现金属迁移、短路、寿命下降和漂移。
传感器的构成
- 基底/换能器:AT-cut 石英晶体微天平(QCM)或压电表面声波(SAW)器件,提供剪切/表面声波振荡并转换质量/键断裂信号
- 敏感电极:金(Au)电极或叉指电极(IDT),承载识别层并耦合声波与电信号
- 界面修饰层:硫醇自组装层(thiol SAM)或生物素化牛血清白蛋白(biotinylated BSA),用于固定识别元件或抗原
- 识别元件:抗体(Ab)、适配体(aptamer)或链霉亲和素(streptavidin),特异性识别目标抗原/配体
- 目标结合物:抗原(antigen)、病毒(virus)、噬菌体(phage)或微球(microsphere),与识别元件形成可断裂键
- 信号读出:锁相环(PLL)、高速计数器或数字扫频电路,检测键断裂噪声与共振频率变化
中文摘要
开发快速、可靠、简便、低成本且能检测低浓度靶标的即时检测生物传感器,一直是研究目标。生物传感器通常以细菌、病毒等生物靶标为对象,利用真实免疫反应中的抗体—抗原结合实现识别。其应用涵盖实验室诊断、药物发现、科研以及环境、食品和农业监测。键断裂法的主要优点是快速、简单,并能区分特异性结合与非特异性结合;这种区分对于在血液等复杂血清中工作尤为重要。键断裂技术既可给出定性结果(检测靶标是否存在),也可给出定量结果(靶标浓度)。该方法为无标记检测,无需对分析物进行预处理。压电换能器(如石英晶体微天平 QCM)通过振荡使结合在表面的颗粒脱离,表面声波(SAW)等其他换能器也被讨论。键断裂事件以电子噪声形式被检测。本综述将多个不同研究领域联系起来,描绘了一个仍在发展中的领域。
英文摘要
It has long been the goal of researchers to develop fast and reliable point-of-care alternatives to existing lab-based tests. A viable point-of-care biosensor is fast, reliable, simple, cost-effective, and detects low concentrations of the target analyte. The target of biosensors is biological such as bacteria or virus and as such, the antibody-antigen bond derived from the real immune response is used. Biosensor applications include lab-based tests for the purposes of diagnostics, drug discovery, and research. Additional applications include environmental, food, and agricultural monitoring. The main merits of the bond-rupture method are quick, simple, and capable of discriminating between specific and non-specific interactions. The separation of specific and non-specific bonds is important for working in real-life complex serums such as blood. The bond-rupture technique can provide both qualitative results, the detection of a target, and quantitative results, the concentration of target. Bond-rupture achieves this by a label-free method requiring no pre-processing of the analyte. A piezoelectric transducer such as the quartz crystal microbalance (QCM) shakes the bound particles free from the surface. Other transducers such as Surface Acoustic Wave (SAW) are also considered. The rupture of the bonds is detected as electronic noise. This review article links diverse research areas to build a picture of a field still in development.