Inexpensive hardware and software for photon statistics and correlation spectroscopy

Benjamin D. Gamari; Dianwen Zhang; Richard E. Buckman; Peker Milas; John S. Denker; Hui Chen; Hongmin Li; Lori S. Goldner

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arXiv · 1206.3332

Inexpensive hardware and software for photon statistics and correlation spectroscopy

Benjamin D. Gamari·Dianwen Zhang·Richard E. Buckman·Peker Milas·John S. Denker·Hui Chen·Hongmin Li·Lori S. Goldner

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Abstract

Single-molecule sensitive microscopies and spectroscopies are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art measurement research capabilities accessible to undergraduates interested in biophysics. We include a pedagogical discussion of the intensity correlation function relevant to FCS and its calculation directly from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for an undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are demonstrated. As implemented, the system has 8 ns timing resolution, outputs to control up to four laser sources, and inputs for as many as four photon-counting detectors.

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Benjamin D. Gamari, Dianwen Zhang, Richard E. Buckman, Peker Milas, John S. Denker, Hui Chen, Hongmin Li, Lori S. Goldner. 2013-11-29. Inexpensive hardware and software for photon statistics and correlation spectroscopy. https://arxiv.org/abs/1206.3332

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