title: Rapid near-infrared fluorescence excitation-emission matrix spectroscopy for multifluorophore characterization using an acousto-optic tunable filter technique.
abstract: We report on a novel acousto-optic tunable filter (AOTF)-based near-infrared (NIR) fluorescence excitation-emission matrix (EEM) spectroscopy technique for rapid multifluorophore characterization. We implement a unique light filtering module design by using cascaded AOTFs coupled with three orthogonally oriented polarizers to effectively remove the side-ripple artifacts of AOTFs as well as by using a pair of AOTFs coupled with two orthogonally oriented polarizers to improve detection efficiency for high-quality fluorescence EEM acquisitions. NIR fluorescence EEM spectroscopy (41 excitation wavelengths ranging from 550 to 950 nm in 10-nm increments; fluorescence emission from 570 to 1000 nm at 10-nm intervals) can be acquired from fluorescence dyes [e.g., diethylthiatricarbocyanine (DTTC) iodide, oxazine 750, and IR 140] within 10 s or even less, illustrating the potential of the AOTF-based NIR EEM technique developed for rapid multifluorophore analysis and characterization in biochemical and biomedical systems.
authors.affiliation: National University of Singapore, Faculty of Engineering, Department of Bioengineering, Optical Bioimaging Laboratory, 9 Engineering Drive 1, Singapore 117576.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D017076:Computer-Aided Design; D054459:Elasticity Imaging Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*