Molecular Probes for Vibrational Imaging of Cellular Targets: Ions and Reactive Species

在化学系化学测量与成像(CMI)和化学结构、动力学和机制B(CSDM-B)项目的支持下，纽约大学的Daniela Buccella教授和她的研究小组正在努力开发基于拉曼光谱技术的响应性分子探针，以研究细胞内的目标。显微技术是生物分析研究中无处不在的工具，能够以高空间和时间分辨率检测细胞和组织中的金属离子和活性物种。实时跟踪这些物种的能力是深入了解它们在生理和病理过程中所扮演角色的关键。在这种背景下，基于拉曼的显微镜技术变得越来越有价值，它提供了许多优于传统荧光显微镜技术的优势。然而，一个重要的缺点是基于振动的检测的灵敏度和特异度较低，对于许多小的和低丰度的细胞目标来说，仍然遥不可及。为了解决这一差距，该项目寻求开发对金属离子和活性物种做出反应的新型指示剂，目标是使用目前看不见的拉曼技术对这些物种进行成像。该奖项还支持与斯佩尔曼学院的教职员工合作开发新的实验室和讲座模块，将化学和生物学整合到斯佩尔曼学院新的顶石研究课程中。该项目专注于建立具有拉曼散射特性的基本分子平台，可以依赖于分析物的方式进行调制。这项工作使新的振动成像探针能够用于受激拉曼散射(SRS)显微镜。所设计的支架利用电荷再分布和电子激发态的调制来实现基于SRS和电子预共振SRS的低丰度和瞬时细胞物种的成像，这些细胞物种本身具有较小的散射截面。具体目标包括开发基于识别的合成指示剂，用于检测与生物相关的金属离子和感测pH，以及用于感测活性氧物种的基于反应的探针。这些指示剂正被应用于纤维素中的开启和比率检测模式，对于猝灭荧光的物种来说，这一点尤其难以实现，因此继续构成生物成像的主要挑战。除了这项工作的更广泛的科学影响外，该项目还包括针对高中女生和大学生的教育推广活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging (CMI) and Chemical Structure, Dynamics, and Mechanisms B (CSDM-B) programs in the Division of Chemistry, Professor Daniela Buccella and her research group at New York University are working to develop responsive molecular probes to investigate intracellular targets based on a technique called Raman spectroscopy. Microscopy techniques are ubiquitous tools in the study of biological analytes, allowing the detection of metal ions and reactive species in cells and tissues with high spatial and temporal resolution. The ability to track these species in real time is key to gaining insight on their roles in physiological and pathological processes. Raman-based microscopy has become increasingly valuable in this context, providing numerous advantages over conventional fluorescence microscopy techniques. An important drawback, however, is the low sensitivity and specificity of vibrational-based detection, for which many small and low abundance cellular targets still remain out of reach. To address this gap, this project seeks to develop novel indicators that are responsive to metal ions and reactive species, with the goal of imaging these species using a Raman technique to which they are currently invisible. This award also supports a partnership with faculty at Spelman College for the development of new laboratory and lecture modules that integrate chemistry and biology into a new capstone research course at Spelman.This project focuses on establishing basic molecular platforms with Raman scattering properties that can be modulated in an analyte-dependent fashion. The work enables new vibrational imaging probes for stimulated Raman scattering (SRS) microscopy. The designed scaffolds take advantage of charge redistribution and modulation of electronic excited states to enable SRS- and electronic pre-resonance-SRS-based imaging of low abundance and transient cellular species that have small scattering cross sections of their own. Specific objectives include the development of recognition-based synthetic indicators for detecting biologically relevant metal ions and sensing pH, as well as reaction-based probes for sensing reactive oxygen species. The indicators are being applied toward turn-on and ratiometric detection modalities in cellulo, which have been particularly difficult to achieve for species that quench fluorescence, and therefore continue to pose a major challenge in bioimaging. In addition to the broader scientific impacts of the work, the project includes educational outreach activities targeting high school girls and college students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.