Investigating the Origin of Molecular Signature Emissions

华盛顿州立大学化学系的亚历山大教授在化学系化学结构、动力学机制B项目资助下，正在开发具有新颖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，能够实现医学诊断和细胞成像的尖端技术。 该项目位于有机化学和光物理学的接口，非常适合各级STEM教育。 该项目将研究和教育紧密结合起来，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。 分析单个分子需要来自该分子的信号必须携带足够的指纹特征，以便可以确认其分子结构身份。 目前的荧光分子在其单分子数据中不提供指纹特征。 因此，荧光可以检测单个分子，但不能识别其分子结构或确定它是由于正信号还是噪声。 为了解决这个问题，本项目通过学习这种分子的设计规则，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，并在各种环境中测试签名发射，以揭示环境因素的影响，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.