Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Engineering, Sun Yat-sen University, Guangzhou 510275, China.
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Biosens Bioelectron. 2015 Jun 15;68:468-474. doi: 10.1016/j.bios.2015.01.033. Epub 2015 Jan 15.
Localized surface plasmon resonance (LSPR) combined with immunoassay shows greatly potential in fast detection of tumor markers. In this paper, a highly sensitive LSPR substrate has been fabricated and modified for direct detection of alpha-fetoprotein (AFP). The biosensor was prepared by interference lithography, and modified by covalently immobilizing anti-AFP on the surface of gold nano-mushroom arrays (GNMA). The modification process was investigated by Vis-NIR reflectance spectra and cyclic voltammogram measurements. We revealed the optical properties of the modified GNMA by measuring the Vis-NIR reflectance spectra and simulating its electric intensity field distribution under light illumination. The GNMA substrate was highly sensitive, with a refractive index sensitivity of ~465 nm/RIU. The substrate can be applied to label-free detection of AFP, with the linear range and the limit of detection determined to be 20-200 ng/mL and 24 ng/mL (S/N=3), respectively. We also demonstrated its clinical application by directly detecting AFP in human serum samples. It is expected that our biosensor could be integrated on microfluidic chips for high-throughput detection in portable early diagnosis, post-operative and point-of-care (POC) in clinical applications.
局部表面等离子体共振 (LSPR) 结合免疫分析在快速检测肿瘤标志物方面显示出巨大的潜力。本文制备了一种高灵敏度的 LSPR 基底，并对其进行了修饰，以用于直接检测甲胎蛋白 (AFP)。该生物传感器通过干涉光刻法制备，并通过将抗 AFP 共价固定在金纳米蘑菇阵列 (GNMA) 的表面进行修饰。通过 Vis-NIR 反射光谱和循环伏安法测量研究了修饰过程。我们通过测量 Vis-NIR 反射光谱并模拟其在光照射下的电场强度分布来揭示修饰后的 GNMA 的光学性质。GNMA 基底具有高灵敏度，折射率灵敏度约为 465nm/RIU。该基底可用于 AFP 的无标记检测，线性范围和检测限分别确定为 20-200ng/mL 和 24ng/mL（S/N=3）。我们还通过直接检测人血清样本中的 AFP 来证明其在临床中的应用。预计我们的生物传感器可以集成到微流控芯片上，用于在便携式早期诊断、术后和临床应用中的即时护理 (POC) 中进行高通量检测。
