Fluorescence quenching of 1-pyrenemethanol by serotonin on the surface of polystyrene latex particles

The fluorescence quenching of 2-pyrenemethanol (PyM) by serotonin (Ser) in polystyrene latex dispersions has been studied by steady-state and time-res olved fluorescence spectroscopy. From steady state fluorescence measurement s, it is found that the quenching is remarkably enhanced on going from an a queous homogeneous solution to a latex dispersion. This is attributed to th at both PyM and Ser are effectively adsorbed onto the latex particles, as e videnced by measurements of the adsorption isotherms. fluorescence decay cu rves of PyM in polystyrene latex dispersions have been successfully analyze d in terms of double exponential functions. The analysis reveals that the q uenching of PyM fluorescence by Ser on polystyrene latex surfaces is mainly operated by a static mechanism, although the contribution of a dynamic mec hanism is not negligible.