School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China.
Anal Chem. 2022 Apr 19;94(15):6011-6016. doi: 10.1021/acs.analchem.2c00633. Epub 2022 Apr 4.
Temperature variation at the nanoscale is pivotal for the thermodynamics and kinetics of small entities. Surface-enhanced Raman spectroscopy (SERS) is a promising technique for monitoring temperature variations at the nanoscale. A key but ambiguous topic is methods to design a sensitive SERS thermometer. Here, we elucidate that the type of chemical bond of molecular probes and the surface chemical bonding effect are crucial for maximizing the sensitivity of the SERS thermometer, as illustrated by the variable-temperature SERS measurements and quantum chemistry calculations for the frequency-temperature functions of a series of molecules. The sensitivity of the frequency-temperature function follows the sequence of triple bond > double bond > single bond, which is available for both aliphatic and aromatic molecules. The surface chemical bonding effect between the SERS substrate and molecular probe substantially increases the sensitivity of the frequency-temperature function. These results provide universally available guidelines for the rational design of a sensitive SERS thermometer by examining the functional groups of molecular probes.
纳米尺度的温度变化对于小实体的热力学和动力学至关重要。表面增强拉曼光谱（SERS）是一种很有前途的监测纳米尺度温度变化的技术。一个关键但不明确的话题是设计灵敏 SERS 温度计的方法。在这里，我们阐明了分子探针的化学键类型和表面化学键合效应对最大限度地提高 SERS 温度计的灵敏度至关重要，这可以通过一系列分子的变温 SERS 测量和量子化学计算的频率-温度函数来说明。频率-温度函数的灵敏度遵循三键>双键>单键的顺序，这对于脂肪族和芳香族分子都适用。SERS 衬底和分子探针之间的表面化学键合效应大大提高了频率-温度函数的灵敏度。这些结果通过检查分子探针的官能团，为通过检查分子探针的官能团来合理设计灵敏的 SERS 温度计提供了普遍适用的指导原则。
