Evaluation of radiation force acting on macromolecules by combination of Brownian dynamics simulation with fluorescence correlation spectroscopy.
Evaluation of radiation force acting on macromolecules by combination of Brownian dynamics simulation with fluorescence correlation spectroscopy.
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DOI：
10.1103/physreve.81.061402
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发表时间：
2010-06
期刊：
影响因子：
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通讯作者：
S. Ito;Naoki Toitani;H. Yamauchi;H. Miyasaka
中科院分区：
文献类型：
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作者：
S. Ito;Naoki Toitani;H. Yamauchi;H. Miyasaka
采用基于布朗动力学模拟的计算方法，研究了聚焦激光束产生的光梯度力对荧光相关光谱的影响。计算结果表明，在较浅的光学力势（TR=298.15 K）中，不考虑光学梯度力的FCS理论模型可以计算出平均分子数和扩散时间的增加。当电位深度>1.0kTR时，模拟的荧光相关曲线与理论模型偏差较大。此外，将光阱条件下的光学力势与温度升高进行积分，得出温度升高对采样区域内的平均粒子数影响不大，但对平均停留时间的影响更为敏感。本研究使用的模拟也提供了一种方法来实验估计分子的极化率从FCS测量。
The effect of optical gradient force from a focused laser beam on the fluorescence correlation spectroscopy (FCS) was investigated by a computing method based on Brownian dynamics simulation. A series of calculations revealed that, in relatively shallow optical force potential up to 1.0kTR (TR=298.15 K), the conventional theoretical model of FCS without consideration of the optical gradient force could evaluate the increase in the average number of molecules and the diffusion time in the potential. On the other hand, large deviation between the simulated fluorescence correlation curve and the theoretical model was observed under the potential depth >1.0kTR. In addition, by integrating the optical force potential with the temperature elevation under optical trapping condition, it was deduced that the temperature rise does not seriously affect the average number of particles in the sampling area, but the average residence time is more sensitively affected by the temperature elevation. The present study using the simulation also provides a method to experimentally estimate molecular polarizabilities from FCS measurements.