Host–Guest Interaction and Hydrogen Bonding Cross-Linking Actuated Smart Two-Dimensional Photonic Hydrogel Sensor of <scp>l</scp>-Histidine
Yuqing Shi, Jie Liu, Jianwei Xin, Bo Han, Yuqi Zhang, Ji‐Jiang Wang
Abstract
Histidine (His) is an essential amino acid that is closely related to the physiological activities of the human body and human health, being used as a biomarker and therapeutic drug for some diseases. It is desirable to accurately and facilely detect His. Here, an l -histidine ( l -His)-sensitive smart two-dimensional photonic hydrogel sensor (CD-2DPCH) was fabricated by modifying NH 2 -β-cyclodextrin (NH 2 -β-CD) onto the poly(acrylamide- Co -acrylic acid) hydrogel containing polystyrene two-dimensional photonic crystal array (PS-2DPC). The volume of the CD-2DPCH sensor shrinks upon response to l -His due to the host–guest interaction between NH 2 -β-CD attached in the hydrogel chains and l -His and the hydrogen bonding interaction between l -His and amides groups on the hydrogel chains. The particle spacing change of ∼95 nm for the PS-2DPC in the hydrogel is achieved, and the chiral recognition of l -His is realized. The particle spacing change of the prepared CD-2DPCH shows a good linear correlation when the l -His concentration changes from 0.1 to 1 and 10 to 400 μM, and the limit of detection is 58 nM. The constructed smart photonic hydrogel sensor was successfully applied to determine l -His in human serum and milk. The fabrication of the sensor is facile, and the detection does not need sophisticated instruments, providing a facile and effective way to identify l -His and a good strategy for sensing other amino acids by modifying different recognition groups.