Photon-by-photon determination of emission bursts from diffusing single chromophores.
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.
Zhang
Kai
K
Department of Chemistry, University of California at Berkeley, and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Yang
Haw
H
D004058:Diffusion; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D017785:Photons
D006046:Gold