Comment on "The effect of the charge density of microemulsion droplets on the bending elasticity of their amphiphilic film", J. Chem. Phys. 114, 10105 (2001)

It is shown that the work by Farago and Gradzielski [J. Chem. Phys. 114, 10105 (2001)] is based on incorrect expressions for the scattering functions, contains a number of other serious defects, and should be revised.Comment: 3 page

Polymer dynamics, fluorescence correlation spectroscopy, and the limits of optical resolution

In recent years, fluorescence correlation spectroscopy has been increasingly applied for the study of polymer dynamics on the nanometer scale. The core idea is to extract, from a measured autocorrelation curve, an effective mean-square displacement function that contains information about the underlying conformational dynamics. The paper presents a fundamental study of the applicability of fluorescence correlation spectroscopy for the investigation of nanoscale conformational and diffusional dynamics. We find that fluorescence correlation spectroscopy cannot reliably elucidate processes on length scales much smaller than the resolution limit of the optics used and that its improper use can yield spurious results for the observed dynamics.Comment: 4 pages, 4 figures, accepted by Physical Review Letter