Molecular photophysics and laser control: Small molecules to fluorescent proteins

分子光物理学和激光控制：小分子到荧光蛋白

• 批准号: RGPIN-2015-05341
• 负责人: Brown, Alexander
• 金额: $ 3.28万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=590371
• 关键词: Molecular; photophysics; laser; control; Small

The research is focused on the development and utilization of theoretical and computational methods for understanding and predicting the structure and properties of molecules underlying biological imaging and new materials as well as for controlling molecular quantum dynamics. Experimental measurements require complementary theoretical and computational study to interpret, and, more importantly, to generalize the observed behaviour to other systems. While the emphasis is on a detailed understanding of excited electronic states, corresponding spectroscopic properties (1-photon absorption, two-photon absorption, fluorescence, phosphorescence,…), and underlying dynamics, the problems to be studied are diverse: (1) Fluorescent proteins are useful probes of biological mechanisms, functions, and structures in molecular and cell biology. There has been great interest in designing FPs with excellent two-photon absorption. We will screen computationally FPs based on non-canonical amino acids (ncAAs) for their two-photon absorption properties. Since the incorporation of ncAAs into proteins is a challenging task experimentally, computational guidance on promising systems is critically important. (2) We will explore recently synthesized fluorescent nucleobase analogs (the natural nucleobases are non-fluorescent) to rationalize the connections between structure and photophysical properties. To assess their use in biological imaging, we will study their binding to natural nucleobases and subsequent effects on absorption/fluorescence properties. (3) Computational tools will be developed for simulating resonance Raman spectra. (4) The BODIPY family of molecules is used widely due to their excellent photophysical properties, i.e., tunable absorption wavelengths, large extinction coefficients, and high quantum yields. Substituted-BODIPY and BODIPY dimers will be examined for a variety of uses, e.g., imaging, molecular photonics… (5) We will compute the photophysical properties of new phosphorescent materials based on bismuth-containing compounds; the rational design of new materials with improved spectral characteristics can save countless experiments. (6) Using tailored laser fields to control quantum dynamics is well-established theoretically and experimentally. The on-going development of shaped laser sources from the mid-infrared to the ultraviolet has lead to the control of a diversity of photophysical and photochemical phenomena, e.g., rovibrational and/or electronic state population transfer, photoisomerization. An important complement to these many experiments is a detailed understanding of the mechanism(s) leading to control. The proposed research will further develop and apply methods for examining laser control in polyatomic molecules. Applications will include photoisomerization and, in particular, photoswitchable proteins.

研究重点是发展和利用理论和计算方法来理解和预测生物成像和新材料的分子结构和性质，以及控制分子量子动力学。实验测量需要互补的理论和计算研究来解释，更重要的是，将观察到的行为推广到其他系统。虽然重点是详细了解激发态、相应的光谱特性（单光子吸收、双光子吸收、荧光、磷光等）和潜在的动力学，但要研究的问题是多种多样的：(1)荧光蛋白是分子和细胞生物学中生物机制、功能和结构的有用探针。设计具有优异双光子吸收性能的FPs引起了人们极大的兴趣。我们将基于非规范氨基酸（ncAAs）的双光子吸收特性来筛选计算FPs。由于在实验中将ncAAs整合到蛋白质中是一项具有挑战性的任务，因此对有前途的系统进行计算指导至关重要。(2)我们将探索最近合成的荧光核碱基类似物（天然核碱基是非荧光的），以理顺结构和光物理性质之间的联系。为了评估它们在生物成像中的应用，我们将研究它们与天然核碱基的结合以及随后对吸收/荧光特性的影响。(3)开发模拟共振拉曼光谱的计算工具。(4) BODIPY家族分子由于其优异的光物理性质，即吸收波长可调、消光系数大、量子产率高而被广泛应用。取代-BODIPY和BODIPY二聚体将被用于多种用途，例如成像、分子光子学……(5)我们将计算基于含铋化合物的新型磷光材料的光物理性质；合理设计改善光谱特性的新材料，可以节省无数的实验。(6)利用定制激光场控制量子动力学已经在理论和实验上得到了验证。从中红外到紫外的成形激光源的持续发展导致了对各种光物理和光化学现象的控制，例如，旋转振动和/或电子态居群转移，光异构化。对这些实验的一个重要补充是对导致控制的机制的详细了解。所提出的研究将进一步发展和应用于检测多原子分子激光控制的方法。应用将包括光异构化，特别是光切换蛋白。