在这项工作中,一种基于原位的生物传感方法,快,和椭偏参数的灵敏测量(Φ,Δ)是建议的。裸露的硅晶片基底被功能化并用于结合溶液中的生物分子。加上基于45°双驱动对称光弹性调制器的椭圆偏光仪,直接确定由于生物分子相互作用而产生的生物层的参数Φ和Δ,可以同时进一步监测溶液的折射率(RI)以及不同相互作用时间的生物层的有效厚度和表面质量密度。为了说明生物传感方法的性能,以免疫球蛋白G(IgG)的免疫传感为例。实验结果表明,该生物传感器对IgG的响应检测限为15ng/mL,数据收集时间以毫秒为单位。此外,该方法具有良好的特异性。这种技术是开发一种能够实现快速和灵敏的新型传感器的有希望的候选者。无标签,操作简单,和具有成本效益的生物传感。
In this work, a biosensing method based on in situ, fast, and sensitive measurements of ellipsometric parameters (Ψ, ∆) is proposed. Bare silicon wafer substrate is functionalized and used to bind biomolecules in the solution. Coupled with a 45° dual-drive symmetric photoelastic modulator-based
ellipsometry, the parameters Ψ and ∆ of biolayer arising due to biomolecular interactions are determined directly, and the refractive index (RI) of the solution and the effective thickness and surface mass density of the biolayer for various interaction time can be further monitored simultaneously. To illustrate the performance of the biosensing method, immunosensing for immunoglobulin G (IgG) was taken as a case study. The experiment results show that the biosensor response of the limit of detection for IgG is 15 ng/mL, and the data collection time is in milliseconds. Moreover, the method demonstrates a good specificity. Such technique is a promising candidate in developing a novel sensor which can realize fast and sensitive, label-free, easy operation, and cost-effective biosensing.