Fluorescence scanning curves

Fig. 1 Separation of flavonoids fluorescence scanning curve of rutin (1), hyperoside (2), quercitrin (3) and quercetin (4).

Fig. 53 Fluorescence scan of femtogram quantities of 2,1,3-naphthoselenodiazole (A) and associated calibration curve (B).

Advanced TCSPC devices usually have spectrum-scan modes that reeord several spectra in different time windows simultaneously. The prineiple is shown in Fig. 5.20. The wavelength is scanned, and for each wavelength a fluorescence decay curve is recorded. The counts in the time channels of the deeay eurve are averaged within selectable time intervals. The averaged counts are stored as functions of the wavelength. Several independent time windows can be used simultaneously. Therefore the efficiency is better than for a system that uses a single window discriminator. 

From the vantage point of TCSPC, imaging by a piezo stage is a slow scan procedure. That means a full fluorescence decay curve is recorded in the current pixel before the scanner moves to the next one. Lifetime images can be therefore acquired by almost any TCSPC module and operation mode. Applications of onedimensional TCSPC with slow scanning are described in [76] and [74]. These... 

The bulk type response curve depends also on surface roughness [4.34]. Reference materials must, therefore, be carefully investigated by angle-scan before use. Angle-scan characteristics of the sample, i.e. the fluorescence intensity recorded at more than one glancing angle near (j>, should not deviate from those of the reference. The measurement must be performed under similar optical conditions. 

Figure 1 Fluorescence spectra taken as single scans at 3 min (lower curve), 24 min (middle curve), and 121 min (upper curve) after mixing a 2 1 (by mass) powder liquid sample.

Figure 6.7 Fluorescence due to the 3) —> 2) transition, where 3) = 6D5/2,F" = 6) and 2) = I6P3/2, F = 5) as the PZT is scanned in time, thereby inducing a proportional phase change. The solid curve is a fit of a constant plus a sinusoidal function. (From Fig. 2, Ref. [211].)...

Fig. 13. Diagram to show the effect of a rising baseline during the recovery of a fluorescence waveform with a boxcar integrator, (a) shows the results with a single scanning aperture and (b) how a second fixed aperture can be used to sample the baseline. The output curve is the difference between the signal in the scanning aperture and that sampling the baseline.

Fig. 11. A layer-by-layer model built by biotin-streptavidin interaction. (A) Angular SPR curves of each layer. The inset shows the SPR minimum position as a function of layer number. (B) SPR, fluorescence angular scans for layers a , b , i , and j .

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