Dunedin, Florida, March 26, 2004 -- The new USB2000-FLG Spectrofluorometer from Ocean Optics is a USB-interface miniature fiber optic spectrometer for low-intensity fluorescence applications (380-1050 nm) that can detect picomolar-range concentrations of fluorophores from surfaces and in liquids and powders.
The USB2000-FLG has two features that prevent it from detecting scattered excitation light from the sample, a phenomena that is especially prevalent in turbid samples: Ag-coated mirrors in the spectrometer optical bench to absorb UV light and improve sensitivity; and, for fluorophores with long fluorescence lifetimes, a time-gated mode that delays the start of spectral data acquisition by 5-500 microseconds after the excitation source is turned off.
The Ag-coated mirrors -- which are manufactured using Ocean Optics' proprietary thin-film technology -- increase reflectance, which increases spectrometer sensitivity. What's more, the mirrors absorb nearly all UV light, virtually eliminating the excitation source spectra from interfering with the sample spectra.
The USB2000-FLG's time-gated mode is enabled via a preloaded microcode, which allows users to select a delay between the excitation light turning on and the start of the spectrometer's integration time, or the amount of time the detector "sees" the sample. This gated mode is particularly useful for measuring fluorophores with long fluorescence lifetimes, such as lanthanides and photoluminescent materials.