Publication: Liquid crystal-based optical sensor for the detection of cysteine through competitive host-guest inclusion
Loading...
Date
2021
Authors
Journal Title
Liquid Crystals
Journal ISSN
Volume Title
Publisher
Taylor and Francis Ltd.
Abstract
A ?-cyclodextrin (?-CD) inclusion complex containing L-cysteine (CYS) as a guest was prepared by freeze drying method. Formation of the inclusion complex was confirmed by powder X-ray diffraction pattern, Fourier-transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The interaction between CYS and ?-CD was also analysed by conductivity measurement in aqueous solution. Thereafter, we developed a liquid crystal (LC)-based sensor system to detect CYS in aqueous solution following the principle of competitive host�guest inclusion. Here the guests sodium dodecyl sulphate (SDS) and CYS compete for the same hydrophobic cavity of host ?-CD. The dark optical image observed by polarising optical microscope confirms that CYS forms inclusion complex with ?-CD leaving SDS free which aligns LCs homeotropically. The constructed LC-based sensor could detect CYS up to 30��M in aqueous solution. Moreover the practical approach of this system was validated by sensing CYS in human serum. � 2020 Informa UK Limited, trading as Taylor & Francis Group.
Description
Keywords
inclusion, L-cysteine, liquid crystal, sensor, ?-cyclodextrin