Nanogram per milliliter-level immunologic detection of alpha-fetoprotein with integrated rotating-resonance microcantilevers for early-stage diagnosis of heptocellular carcinoma
Nanogram per milliliter-level immunologic detection of alpha-fetoprotein with integrated rotating-resonance microcantilevers for early-stage diagnosis of heptocellular carcinoma
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DOI：
10.1007/s10544-008-9223-2
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发表时间：
2009-02-01
影响因子：
2.8
通讯作者：
Yu, Haitao
中科院分区：
文献类型：
--
作者：
Liu, Yongjing;Li, Xinxin;Yu, Haitao
甲胎蛋白（AFP）是肝癌的重要标志物，采用纳克/毫升水平的超低浓度检测有利于早期预后和疾病诊断。AFP等抗原的现场快速检测非常需要创新的微/纳米技术。为了满足这一要求，一种先进的共振微悬臂梁被开发出来，并用于筛选纳克每毫升水平的肿瘤标志物。谐振式微悬臂梁的传感原理是测量频率偏移与比吸附质量的关系。与电磁谐振激励和压阻读出元件集成在芯片上，微悬臂梁传感器操作在旋转谐振模式，以提高灵敏度和分辨率，以特定的质量吸附。在用预先固定的抗AFP抗体检测AFP之前，用酶联免疫吸附测定实验确认抗原-抗体特异性结合。通过在液体中实现特定的反应，并在实验室空气环境中阅读传感器信号，该微机械传感器实现了2 ~ 20 ng/ml的灵敏度范围。为了有效地抑制串扰信号和提高分辨率，悬臂梁表面的不敏感区域用2-[甲氧基（聚乙烯氧基）丙基]三甲氧基硅烷预修饰以使非特异性生物吸附最小化。实验结果表明，AFP的检测限优于2ng/mL。这种无标记的谐振式微悬臂梁传感器在低成本甚至一次性使用的肿瘤早期诊断和预后方面具有很大的应用前景。
Nanogram per milliliter-level ultra-low concentration detection of alpha-fetoprotein (AFP), which is an important marker for heptocellular carcinoma, is in favor of early-stage prognosis and disease diagnosis. On-the-spot rapid detection of such antigens as AFP highly requires innovative micro/nano techniques. To meet this requirement, an advanced resonant microcantilever is developed and used for screening the tumor marker at nanogram per milliliter level. The sensing principle of the resonant microcantilever is measuring frequency-shift versus specific-adsorbed mass. With both electromagnetic resonance-exciting and piezoresistive readout elements on-chip integrated, the microcantilever sensor is operated in a rotating resonance mode to improve sensitivity and resolution to specific mass adsorption. Prior to detection of AFP with previously immobilized anti-AFP antibody, the antigen-antibody specific-binding is confirmed with an enzyme linked immunosorbent assay experiment. By implementing the specific reaction in liquid and reading out the sensor signal in lab air environment, the micromechanical sensor has achieved the sensitive scale between 2 and 20 ng/ml. To effectively depress cross-talk signal and improve resolution, the insensitive regions of the cantilever surface are pre-modified with 2-[methoxy (polyethyleneoxy) propyl] trimethoxysilane for nonspecific bio-adsorption minimization. Finally, a better AFP detecting limit than 2 ng/mL is experimentally achieved. The label-free resonant microcantilever sensor is promising in low-cost or even disposable early-stage prognosis and diagnosis of tumors.