College of Chemistry and Environment, Southwest Minzu University, Chengdu, Sichuan 610041, China.
Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, College of Chemistry and Environment, Southwest Minzu University, Chengdu, Sichuan 610041, China.
Soft Matter. 2023 Jul 5;19(26):4880-4890. doi: 10.1039/d3sm00513e.
Potassium ions (K) play crucial roles in many biological processes. Abnormal K levels in the body are usually associated with physiological disorders or diseases, and thus, developing K-sensitive sensors/devices is of great importance for disease diagnosis and health monitoring. Herein, we report a K-sensitive photonic crystal hydrogel (PCH) sensor with bright structural colors for efficient monitoring of serum potassium. This PCH sensor consists of a poly(acrylamide--isopropylacrylamide--benzo-15-crown-5-acrylamide) (PANBC) smart hydrogel with embedded FeO colloidal photonic crystals (CPCs), which could strongly diffract visible light and endow the hydrogel with brilliant structural colors. The rich 15-crown-5 (15C5) units appended on the polymer backbone could selectively bind K ions to form stable 2 : 1 [15C5]/K supramolecular complexes. These bis-bidentate complexes served as physical crosslinkers to crosslink the hydrogel and contracted its volume, and thus reduced the lattice spacing of FeO CPCs and blue-shifted the light diffraction, and finally reported on the K concentrations by a color change of the PCH. Our fabricated PCH sensor possessed high K selectivity and pH- and thermo-sensitive response performances to K. Most interestingly, the K-responding PANBC PCH sensor could be conveniently regenerated simple alternate flushing with hot/cold water due to the excellent thermosensitivity of the introduced PNIPAM moieties into the hydrogel. Such a PCH sensor provides a simple, low-cost and efficient strategy for visualized monitoring of hyperkalemia/hypokalemia, which will significantly promote the development of biosensors.
钾离子 (K) 在许多生物过程中发挥着关键作用。体内 K 水平异常通常与生理紊乱或疾病有关，因此，开发对 K 敏感的传感器/设备对于疾病诊断和健康监测非常重要。在此，我们报告了一种具有明亮结构颜色的 K 敏感光子晶体水凝胶 (PCH) 传感器，可有效监测血清钾。这种 PCH 传感器由聚（丙烯酰胺-异丙基丙烯酰胺-苯并-15-冠-5-丙烯酰胺）（PANBC）智能水凝胶和嵌入的 FeO 胶体光子晶体（CPC）组成，它可以强烈衍射可见光，并赋予水凝胶绚丽的结构颜色。聚合物主链上丰富的 15-冠-5（15C5）单元可以选择性地结合 K 离子形成稳定的 2:1 [15C5]/K 超分子配合物。这些双齿配合物充当物理交联剂来交联水凝胶并收缩其体积，从而减小 FeO CPC 的晶格间距并使光衍射蓝移，最终通过 PCH 的颜色变化报告 K 浓度。我们制造的 PCH 传感器具有高 K 选择性和对 K 的 pH 和温度敏感的响应性能。最有趣的是，由于引入水凝胶中的 PNIPAM 部分的出色热敏性，对 K 有响应的 PANBC PCH 传感器可以通过简单的冷热交替冲洗方便地再生。这种 PCH 传感器为可视化监测高钾血症/低钾血症提供了一种简单、低成本和高效的策略，将极大地促进生物传感器的发展。
