Institute of Imaging and Biomedical Photonics, College of Photonics, National Yang Ming Chiao Tung University, Guiren District, Tainan 71150, Taiwan.
Department of Basic Science, Faculty of Engineering, The British University in Egypt, El Sherouk City 11837, Cairo, Egypt.
Biosensors (Basel). 2021 Mar 13;11(3):81. doi: 10.3390/bios11030081.
An optical and dielectric biosensor based on a liquid crystal (LC)-photopolymer composite was established in this study for the detection and quantitation of bovine serum albumin (BSA). When the nematic LC E7 was doped with 4-wt.% NOA65, a photo-curable prepolymer, and photopolymerized by UV irradiation at 20 mW/cm for 300 s, the limit of detection determined by image analysis of the LC optical texture and dielectric spectroscopic measurements was 3400 and 88 pg/mL for BSA, respectively, which were lower than those detected with E7 alone (10 μg/mL BSA). The photopolymerized NOA65, but not the prepolymer prior to UV exposure, contributed to the enhanced optical signal, and UV irradiation of pristine E7 in the absence of NOA65 had no effect on the optical texture. The effective tilt angle , calculated from the real-part dielectric constant ', decreased with increasing BSA concentration, providing strong evidence for the correlation of photopolymerized NOA65 to the intensified disruption in the vertically oriented LC molecules to enhance the optical and dielectric signals of BSA. The optical and dielectric anisotropy of LCs and the photo-curable dopant facilitate novel quantitative and signal amplification approaches to potential development of LC-based biosensors.
本研究建立了一种基于液晶（LC）-光聚合物复合材料的光学和介电生物传感器，用于检测和定量牛血清白蛋白（BSA）。当向向列相 LC E7 中掺杂 4wt.% 的 NOA65（一种可光聚合的预聚物），并在 20 mW/cm 的紫外光下辐照 300 s 进行光聚合时，通过 LC 光学纹理的图像分析和介电光谱测量确定的检测限分别为 3400 和 88 pg/mL，均低于单独使用 E7 时的检测限（10 μg/mL BSA）。光聚合的 NOA65，而不是在紫外光暴露前的预聚物，有助于增强光学信号，并且在没有 NOA65 的情况下对原始 E7 进行紫外光照射对光学纹理没有影响。有效倾斜角 ，由实部介电常数 '计算得出，随着 BSA 浓度的增加而减小，为光聚合的 NOA65 与增强的垂直取向 LC 分子的破坏有关提供了有力证据，从而增强了 BSA 的光学和介电信号。LC 的光学各向异性和光可固化掺杂剂有利于新型定量和信号放大方法，为基于 LC 的生物传感器的潜在发展提供了可能。
