Nanoparticle sizing method based on fluorescence anisotropy analysis

Size Characterization of Glutathione-Protected Gold Nanoclusters in the Solid, Liquid and Gas Phases

“…As also reported in a pioneering work on fluorescence anisotropy of BSA protein protected Au 25 nanoclusters, we explored fluorescence lifetimes with polarized excitation. Nanocluster size evaluation can be performed by measuring the rotational diffusion coefficient, which is sensitive to particle size . We used a mixture of methanol/glycerol (10:90%, v/v) in order to slow down Au­(SG) cluster motion in a high viscosity solvent, resulting in measurable anisotropy decay.…”

“…Nanocluster size evaluation can be performed by measuring the rotational diffusion coefficient, which is sensitive to particle size. 26 We used a mixture of methanol/glycerol (10:90%, v/v) in order to slow down Au(SG) cluster motion in a high viscosity solvent, resulting in measurable anisotropy decay. The anisotropy decay of TBA−Au 18 (SG) 14 in methanol/glycerol (10:90%, v/v) is shown in Figure 3c (with excitation at 500 nm).…”

“…However, in the case of such small clusters, evaluating size becomes difficult due to the lack of sensitivity of DLS techniques. Fluorescence anisotropy analysis may be an alternative for nanoparticle sizing as it allows determining the rotational diffusion coefficient . Fluorescence anisotropy measurements have been used to evaluate the size modification of bovine serum albumin (BSA)-Au 25 clusters as the pH is reduced from 7 to 3.1 .…”

“…Fluorescence anisotropy analysis may be an alternative for nanoparticle sizing as it allows determining the rotational diffusion coefficient. 26 Fluorescence anisotropy measurements have been used to evaluate the size modification of bovine serum albumin (BSA)-Au 25 clusters as the pH is reduced from 7 to 3.1. 27 Indeed, quantum sized gold nanoclusters have been found to present considerable fluorescence anisotropy.…”