逐个光子确定扩散单发色团的发射脉冲。

Photon-by-photon determination of emission bursts from diffusing single chromophores.

作者信息

Zhang Kai, Yang Haw

机构信息

Department of Chemistry, University of California at Berkeley, and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

出版信息

J Phys Chem B. 2005 Nov 24;109(46):21930-7. doi: 10.1021/jp0546047.

DOI:10.1021/jp0546047

PMID:16853850

Abstract

One of the difficulties in diffusion-type single-molecule experiments is the determination of signal amid photon-counting noise. A commonly used approach is to further average the noisy time trace by binning, followed by placing a threshold to discriminate signal from background. The choice of smoothing parameters and the placement of the threshold may impact on the efficiency with which the information-rich region can be harvested, among other potential complications. Here we introduce a procedure that operates on the data sequence photon by photon, thereby relieving the incertitude in choosing binning-thresholding parameters. We characterize this procedure by detecting the two-photon emission bursts from diffusing single gold nanoparticles. The results support our burst-finding procedure as a reliable and efficient way of detecting and harvesting photon bursts from diffusing experiments.

摘要

扩散型单分子实验中的一个难点是在光子计数噪声中确定信号。一种常用方法是通过对分箱进一步平均有噪声的时间轨迹，然后设置一个阈值来区分信号和背景。平滑参数的选择和阈值的设置可能会影响获取信息丰富区域的效率以及其他潜在的复杂情况。在这里，我们介绍一种逐光子对数据序列进行操作的方法，从而消除选择分箱阈值参数时的不确定性。我们通过检测扩散的单个金纳米颗粒的双光子发射脉冲来表征这一方法。结果支持我们的脉冲发现方法是一种从扩散实验中检测和获取光子脉冲的可靠且高效的方式。