Illumination of a solution of 7a flowing through a microscaled channel with an activation source generates 7b. The emissive species travels through the channel to reach an area irradiated with an excitation source. The emitted photons are detected at this position, and their number is plotted against the delay from activation. The resulting profiles show a decrease in delay with an increase in flow rate from 11 cm s−1 (a) to 16 m s−1 (b) (reproduced with permission from [150]).
