中国科学技术大学张国庆团队用磷光光谱研究碘化吖啶的水-冰微观结构和水化状态。相关研究成果于2024年4月11日发表于国际顶尖学术期刊《德国应用化学》。

冰被认为在生命起源中发挥了重要作用，部分原因是它能够浓缩有机分子并提高反应效率。然而，研究冰中有机分子的技术是基于吸收的，这限制了测量的灵敏度。

该文中，研究人员介绍了一种基于发射的方法来研究水冰中的有机分子：磷光显示出高灵敏度，这取决于有机盐探针碘化吖啶（ADI）的水合状态。所设计的ADI水系统发射磷光，当温度高于110K且浓度为10^-5M量级时，磷光会受到严重干扰，这表明ADI的水合作用发生了变化。

使用ADI磷光探针，发现水冰的微观结构，即晶体与玻璃质，可以强烈地由痕量（低至10^-5M）的水溶性有机分子决定。与冷冻SEM图像和温度相关的拉曼光谱数据一致，ADI在更多结晶的冰中脱水，在更多玻璃质的冰中水合。目前的研究是使用更灵敏的光谱技术在更低的浓度和更宽的温度范围内，研究水-有机物相互作用的起点。

附：英文原文

Title: Water-Ice Microstructures and Hydration States of Acridinium Iodide Studied by Phosphorescence Spectroscopy

Author: Hongping Liu, Hao Su, Ning Chen, Jie Cen, Jiajia Tan, Baicheng Zhang, Xiaoyu Chen, Aoyuan Cheng, Shengquan Fu, Xiaoguo Zhou, Shilin Liu, Xuepeng Zhang, Shiyong Liu, Yi Luo, Guoqing Zhang

Issue&Volume: 2024-04-11

Abstract: Ice has been suggested to have played a significant role in the origin of life partly owing to its ability to concentrate organic molecules and promote reaction efficiency. However, the techniques for studying organic molecules in ice are absorption-based, which limits the sensitivity of measurements. Here we introduce an emission-based method to study organic molecules in water ice: the phosphorescence displays high sensitivity depending on the hydration state of an organic salt probe, acridinium iodide (ADI). The designed ADI aqueous system exhibits phosphorescence that can be severely perturbed when the temperature is higher than 110 K at a concentration of the order of 10-5M, indicating changes in hydration for ADI. Using the ADI phosphorescent probe, it is found that the microstructures of water ice, i.e., crystalline vs. glassy, can be strongly dictated by a trace amount (as low as 10-5M) of water-soluble organic molecules. Consistent with cryoSEM images and temperature-dependent Raman spectral data, the ADI is dehydrated in more crystalline ice and hydrated in more glassy ice. The current investigation serves as a starting point for using more sensitive spectroscopic techniques for studying water-organics interactions at a much lower concentration and wider temperature range.

DOI: 10.1002/anie.202405314

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202405314