Wang Ruiqin, Zhang Mengxin, Guan Ying, Chen Mao, Zhang Yongjun
Key Laboratory of Functional Polymer Materials and State Key Laboratory of Medicinal Chemical Biology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900, China.
Soft Matter. 2019 Aug 14;15(30):6107-6115. doi: 10.1039/c9sm00958b. Epub 2019 Jul 8.
CO-monitoring plays an important role in medicine, environmental sciences, and food industries. Here, a new CO-responsive hydrogel film was fabricated from branched polyethyleneimine (BPEI) and partially oxidized dextran (PO-Dex) via layer-by-layer (LBL) assembly, based on the in situ Schiff base reaction between the two polymers. The swelling behaviours of the films were studied using Fabry-Perot fringes on their reflection spectra. Like ordinary hydrogels, the BPEI/PO-Dex films swell in water. In addition, they swell to a larger degree when CO is introduced, due to the reaction between CO and the amino groups in BPEI. The CO-induced swelling can be reported by the shift of the Fabry-Perot fringes on their reflection spectra; therefore, the BPEI/PO-Dex film can be used as an optical sensor for dissolved CO. In the new sensor, the BPEI/PO-Dex film acts as a CO-sensing material and Fabry-Perot cavity simultaneously. The introduction of ordered structure is no longer required. The response of the sensor to CO is linear and reversible. Unlike other hydrogel-based sensors that suffer from a slow response, the new sensor can respond to CO quickly, making it applicable for real-time, continuous monitoring of CO levels in solution.
一氧化碳监测在医学、环境科学和食品工业中发挥着重要作用。在此，基于两种聚合物之间的原位席夫碱反应，通过层层（LBL）组装由支化聚乙烯亚胺（BPEI）和部分氧化的葡聚糖（PO-Dex）制备了一种新型的一氧化碳响应水凝胶薄膜。利用法布里-珀罗条纹对其反射光谱进行研究，以考察薄膜的溶胀行为。与普通水凝胶一样，BPEI/PO-Dex薄膜在水中会溶胀。此外，由于一氧化碳与BPEI中的氨基发生反应，当引入一氧化碳时它们会溶胀到更大程度。一氧化碳诱导的溶胀可以通过其反射光谱中法布里-珀罗条纹的移动来报告；因此，BPEI/PO-Dex薄膜可用作溶解一氧化碳的光学传感器。在这种新型传感器中，BPEI/PO-Dex薄膜同时充当一氧化碳传感材料和法布里-珀罗腔。不再需要引入有序结构。该传感器对一氧化碳的响应是线性且可逆的。与其他基于水凝胶的传感器响应缓慢不同，这种新型传感器能够快速响应一氧化碳，使其适用于实时、连续监测溶液中的一氧化碳水平。
