Investigating the Origin of Molecular Signature Emissions

在这项由化学系化学结构、动态和机理B计划资助的项目中，华盛顿州立大学化学系的Alexander Li教授正在开发具有新型光学性质的新型荧光分子。这些分子是有用的探针和成像试剂，使医疗诊断和细胞成像中的尖端技术成为可能。该项目位于有机化学和光物理的交界处，非常适合各级STEM教育。该项目将研究和教育紧密结合在一起，为从K-12到研究生的学生提供最高水平的教育培训，包括那些在科学领域代表性不足的学生。识别单个分子超越了单分子检测，代表了化学分析的极限。要分析单个分子，需要来自该分子的信号必须带有足够的指纹特征，才能确认其分子结构的同一性。目前的荧光分子在其单分子数据中不提供指纹签名。因此，荧光可以检测到单个分子，但无法识别其分子结构，也无法确定它是由于正信号还是由于噪声。为了解决这一问题，本项目通过学习此类分子的设计规则，揭示光-分子相互作用在签名发射中的作用，确定签名机制的单光子过程或双光子过程，并在不同环境中测试签名发射以揭示环境因素的影响，来开发具有签名发射的分子。

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Alexander Li of the Department of Chemistry at Washington State University is developing new classes of fluorescent molecules with novel optical properties. These molecules are useful probes and imaging reagents that enable cutting-edge technologies in medical diagnostics and cell imaging. The project lies at the interface of organic chemistry and photo-physics and is well suited for STEM educations at all levels. This project closely integrates research and education and provides the highest level of educational training for students ranging from K-12 to post-graduate students, including those underrepresented in sciences. Identifying a single molecule goes beyond single-molecule detection and represents the ultimate limit in chemical analysis. To analyze a single molecule requires that the signals originated from this molecule must carry enough fingerprint signatures so that its molecular structural identity can be confirmed. Current fluorescent molecules do not offer fingerprint signatures in their single-molecular data. As a result, fluorescence can detect a single molecule, but cannot identify its molecular structure or determine whether it is due to positive signal or noise. To address this problem, this project develops molecules with signature emission by learning the design rules for such molecules, unveiling the role of light-molecule interactions in signature emission, determining the one-photon process or two-photon process for the signature mechanism, and testing signature emission in various environments to reveal the impacts of environmental factors.