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Signal Amplification in an Optical and Dielectric Biosensor Employing Liquid Crystal-Photopolymer Composite as the Sensing Medium

Authors :
Hassanein Shaban
Shih-Chun Yen
Mon-Juan Lee
Wei Lee
Source :
Biosensors, Vol 11, Iss 3, p 81 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

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/cm2 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 θ, calculated from the real-part dielectric constant ε’, 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.

Details

Language :
English
ISSN :
20796374
Volume :
11
Issue :
3
Database :
Directory of Open Access Journals
Journal :
Biosensors
Publication Type :
Academic Journal
Accession number :
edsdoj.038d01953a974deeb6c82c6ecd8adee4
Document Type :
article
Full Text :
https://doi.org/10.3390/bios11030081