Preparation of DNA-functionalized surfaces for simultaneous homeotropic orientation of liquid crystals and optical recognition of analytes: application to the determination of progesterone
- 15 Downloads
The work describes a simplified method for the preparation of liquid crystal (LC) bioassay using DNA-based capture molecules and having lower detection limits. The capture DNA probes of the stem-loop structure were immobilized on the surface of a glass slide. A homeotropic orientation of LC molecules can be obtained with the proper surface coverage of capture DNA probes. In the presence of analytes (specifically shown here for the progesterone as a model analyte), the molecular binding between capture DNA probes and progesterone opens the loop of the capture DNA probes. The opened sequence is then amenable to hybridization with a reporter DNA probe that is immobilized on gold nanoparticles. This changes the surface microstructure, disrupts the orientation of LC molecules, and results in an enhanced optical response, expressed as the average grey value of the images. This new kind of surface treatment for simultaneous recognition of target molecules and homeotropic anchoring of LCs reduces the number of preparation steps and makes the process of LC bioassay easier. This method has a detection limit as low as 0.1 pmol·L−1 of progesterone.
KeywordsAuNPs Signal amplification Stem-loop structure Triethoxsilylbutyraldehyde Self-assembled Silanization Monolayer Surface microstructure Average grey value Bioassay
This research is funded by the Chongqing Research Program of Basic Research and Frontier Technology (cstc2018jcyjAX0165).
Compliance with ethical standards
The author(s) declare that they have no competing interests.
- 20.Ren HH, An ZF, Jang CH (2019) Liquid crystal-based aptamer sensor for sensitive detection of bisphenol a. Microchem J 18:31227–3122XGoogle Scholar