HORIBA Scientific introduces a new instrument: the MF2. Fluorescence scientists now have an important tool to help understand real-time natural processes. The MF2 is based on unique technologies - developed at HORIBA Scientific - to increase the rate of data-collection by 10,000 times and dynamic range by 1000 times over conventional approaches!

Existing fluorescence systems offer sensitivity, selectivity and wide time-resolution. With instruments from HORIBA Scientific, we can measure the duration of molecular events from picoseconds to nanoseconds - and longer. The two best methods for this are "Time Correlated Single-Photon Counting" (TCSPC), and "Phase and Modulation" (frequency domain). HORIBA Scientific is in the unrivalled position of offering the highest-performing instruments using both methods. Frequency domain records the response of a photomultiplier tube, revealing the change in the phase and modulated amplitude of the sinusodial fluorescence emission relative to the excitation beam. This measurement is repeated at several modulation frequencies to give the fluorescence lifetime. The sequential nature of this method, however, requires many minutes to complete an experiment. Clearly, an opportunity existed to improve this approach.

We at HORIBA Scientific used recent advances in frequency synthesis to develop wholly new technologies to bypass conventional limitations. By grouping multiple frequencies into one high-frequency waveform and greatly expanding the available frequency range, we decreased the time it takes to measure a fluorescence lifetime from minutes to milliseconds, a 10,000-fold change. We call this revolution in instrumentation the MF2, which delivers previously unavailable experimental speed and performance.

HORIBA Scientific's revolutionary, fast MF2 technique....

Fig. 1.
Fluorescence signal (red) elicited from a modulated excitation beam composed of eight frequencies (light blue) mixed together. The new MF2 uses this method of excitation to characterize fluorescence lifetimes within 10 milliseconds.

The MF2 combines speed and precision for real-time kinetics measurements of fluorescent life-times....


Fig. 2.
Change in phase-angle (left) and modulation (right) after adding POPOP to 9-CA in MeOH. Note how the phase-angle drops, while the modulation rises, when the POPOP is added.

An actual example is shown of 9-cyanoanthracene (τ = 11.8 ns) in methanol was placed in a cuvette and excited at 340 nm with four multiplexed frequencies. The fluorescence response over the course of 10 s was recorded through a long-pass Schott KV filter (λ > 370 nm). Notice the change in phase-angle and modulation after addition of POPOP (τ = 1.32 ns) in methanol. Time resolution was 50 ms per data set, giving a clear view of the mixing event. The ~ 50:50 mixture thereafter contained two lifetime components, with a concomitant change in response.

The MF2 takes advantage of our easy and powerful FluorEssence™ software, using a single window to set up the entire spectroscopic experiment (Fig. 3). Rather than choosing the frequencies to run the experiment, the MF2 uses an entirely new paradigm: you decide on a likely range of lifetimes, and the software chooses the frequencies for you!

Fig. 3.
Simple setup of an MF2 lifetime kinetics experiment in our FluorEssence™ software.

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