Aggregation Induced Emissive Liquid Crystals‐Polymer Composite Membrane for Dual‐Channel Analysis of Parathyroid Hormone

ABSTRACT Parathyroid hormone (PTH) is an important factor in maintaining blood calcium levels in the human body. Therefore, monitoring PTH levels is essential for assessing the various diseases progression and managing overall health. In this study, a fluorescence and optical sensor based on an aggregation‐induced emissive liquid crystal photopolymer (AIE‐LC‐Poly) film was established for the qualitative and quantitative detection of PTH. The specific interaction between PTH and anti‐PTH on the substrate surface was utilized, and variations in orientation and aggregation state of the fluorescent LCs were evaluated by both optic and fluorescent means. The detection limit for PTH using optical image was above 10 µg/mL, while fluorescence detection achieved a much lower limit of 1 ng/mL. Additionally, the photopolymer further amplified the detection signals by strengthening the AIE effect of the fluorescent LCs in initiate state, and enhancing the disturbance of LCs ordered orientation upon PTH addition. Ultimately, the detection limits for PTH were reduced to 0.01 µg/mL for optical detection and 50 pg/mL for fluorescence detection. The quantitative and sensitive AIE‐LC‐Poly biosensing technology presented here sets the stage to develop LC‐based sensor for biomedical applications without labeling.