Digitally synthesized beat frequency-multiplexed fluorescence lifetime spectroscopy

作者:Chan Jacky C K*; Diebold Eric D; Buckley Brandon W; Mao Sien; Akbari Najva; Jalali Bahram
来源:Biomedical Optics Express, 2014, 5(12): 4428-4436.
DOI:10.1364/BOE.5.004428

摘要

Frequency domain fluorescence lifetime imaging is a powerful technique that enables the observation of subtle changes in the molecular environment of a fluorescent probe. This technique works by measuring the phase delay between the optical emission and excitation of fluorophores as a function of modulation frequency. However, high-resolution measurements are time consuming, as the excitation modulation frequency must be swept, and faster low-resolution measurements at a single frequency are prone to large errors. Here, we present a low cost optical system for applications in real-time confocal lifetime imaging, which measures the phase vs. frequency spectrum without sweeping. Deemed Lifetime Imaging using Frequency-multiplexed Excitation (LIFE), this technique uses a digitally-synthesized radio frequency comb to drive an acousto-optic deflector, operated in a cat's-eye configuration, to produce a single laser excitation beam modulated at multiple beat frequencies. We demonstrate simultaneous fluorescence lifetime measurements at 10 frequencies over a bandwidth of 48 MHz, enabling high speed frequency domain lifetime analysis of single-and multi-component sample mixtures.

  • 出版日期2014-12-1