Zhao Jifang, Du Jiahui, Qin Tianyou, Zhang Sean Xiao-An, Sheng Lan
State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China.
Department of Biochemistry and Molecular Biology, College of Basic Medicine Science, Jilin University, Changchun, 130012, China.
Adv Sci (Weinh). 2025 Jul;12(26):e2503779. doi: 10.1002/advs.202503779. Epub 2025 Apr 2.
The temperature response window is a very critical parameter for evaluating temperature sensing performance of thermofluorochromic materials, and its regulation has long been a key focus in this field. Especially, the indication of refrigeration temperature is of great significance as it relates to public health and food safety. However, developing fluorochromic materials capable of visually reading out refrigeration temperature remains challenges. Herein, a "confined eutectic" strategy is proposed to develop fluorochromic materials that are easy to prepare and can naked-eye recognition of refrigeration temperature. Through supramolecular interactions between dopant and host matrix, eutectic micro-domains are formed and their crystallization point is effectively lowered into the range of 0-10 °C. The excellent crystalline host matrix provides a "confinement" effect, and thereby enhancing the crystallinity of the eutectics, which enables precise aggregation and dispersion of surrounding fluorophores, resulting in significant color changes. The mechanism is validated through variable-temperature fluorescence spectra, confocal laser scanning microscopy and phase diagram analysis. The obtained materials exhibit high fluorescence color contrast, and can apply to diverse dyes for multi-mode and multi-color readout. This work not only open up new insights for refrigeration temperature responsive fluorochromic materials, but also provides a new way for visual regulation crystallinity.
温度响应窗口是评估热致荧光变色材料温度传感性能的一个非常关键的参数，其调控长期以来一直是该领域的重点。特别是，制冷温度的指示具有重要意义，因为它关系到公众健康和食品安全。然而，开发能够直观读出制冷温度的荧光变色材料仍然面临挑战。在此，提出了一种“受限共晶”策略来开发易于制备且能裸眼识别制冷温度的荧光变色材料。通过掺杂剂与主体基质之间的超分子相互作用，形成共晶微区，其结晶点有效地降低到0-10℃范围内。优异的结晶主体基质提供“限制”效应，从而提高共晶的结晶度，使周围荧光团能够精确聚集和分散，导致显著的颜色变化。通过变温荧光光谱、共聚焦激光扫描显微镜和相图分析对该机制进行了验证。所获得的材料表现出高荧光颜色对比度，可应用于多种染料以实现多模式和多颜色读出。这项工作不仅为制冷温度响应荧光变色材料开辟了新的见解，也为可视化调控结晶度提供了新途径。
