22.07.2013 Views

Principles of Fluorescence Spectroscopy

Principles of Fluorescence Spectroscopy

Principles of Fluorescence Spectroscopy

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

PRINCIPLES OF FLUORESCENCE SPECTROSCOPY 155<br />

P4.6. Data Acquisition Times Using TCSPC With Microsecond<br />

Decay Times: Calculate the time needed to acquire<br />

the data in Figure 4.45. Assume the lifetime <strong>of</strong><br />

[Ru(bpy) 3 ] 2+ is 400 ns and that one photon is detected<br />

for each excitation pulse. Calculate the data acquisition<br />

time to obtain the same data using TCSPC with the same<br />

pulse repetition rate and a 1% count rate.<br />

P4.7. Data Acquisition Times Using TCSPC With Nanosecond<br />

Decay Times: Suppose the lifetime <strong>of</strong> a fluorophore is 4<br />

ns. Determine the conditions needed for TCSPC. Calcu-<br />

late the time required to count 4 x 10 6 photons with 1<br />

photon counted per 100 excitation pulses. Consider dead<br />

times <strong>of</strong> 2 :s and 120 ns.<br />

P4.8. Calculation <strong>of</strong> Fractional Intensities and Pre-Exponential<br />

Factors: Suppose two compounds have equal quantum<br />

yields but different lifetimes <strong>of</strong> τ 1 = 1 :s and τ 2 = 1<br />

ns. If a solution contains an equimolar amount <strong>of</strong> both<br />

fluorophores, what is the fractional intensity <strong>of</strong> each fluorophore?

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!