Erratum: “Observation of buried water molecules in phospholipid membranes by surface sum-frequency generation spectroscopy” [J. Chem. Phys. 131, 161107 (2009)]

Theoretical vibrational sum-frequency generation spectroscopy of water near lipid and surfactant monolayer interfaces. II. Two-dimensional spectra

“…[38][39][40][41] Due to lipid headgroup-water electrostatics, water OH chromophores on average point upwards near negatively charged interfaces and point downwards near positively charged interfaces, resulting respectively in positive and negative SFG spectra. 20,24,42,43 The SFG spectrum for water at a zwitterionic interface is similar to the anionic case, indicating average upward orientation of OH chromophores. However, the peak height of the spectrum depends on lipid headgroup-water hydrogen bonding as well as the ionic strength of the solution.…”

Sum frequency spectroscopy of the hydrophobic nanodroplet/water interface: Absence of hydroxyl ion and dangling OH bond signatures

“…Based on our earlier experiments [54,55], we found that surfactant anions can be detected on the surface with both their C H and S O stretch modes (that have comparable SF cross-sections) from concentrations in the order of 5-10 M (on d 34 -hexadecane droplets in D 2 O as used in this study). Since the SF cross section for the C H modes is comparable to that of the O D modes [56], we may expect changes in the SF signal at comparable concentrations, i.e. from pD ∼9.…”

Sum-frequency vibrational spectroscopic studies of Langmuir monolayers

“…In such cases, polar orientation of interfacial water molecules underneath a zwitterionic lipid monolayer is difficult to determine with conventional SFVS. Sovago et al tried to do so for interfacial water under DPPC and DPPE monolayers by applying the maximum entropy analysis to the measured SF intensity spectra, and concluded that the average polar orientations of water molecules under DPPC and DPPE monolayers were the same as that under a positively charged lipid monolayer [119]. However, recent phase-sensitive SFVS measurement found that they are the same as that under a negatively charged lipid monolayer [120].…”