A Quantitative Comparison of Chlorophyll Bilayers Formed With and Without Solvent

Abstract

Bimolecular lipid membranes are formed from solutions containing lecithin and chlorophyll‐a (chl‐a) in various molar ratios. Both the Mueller‐Ruding technique as well as the solvent free, Montal‐Mueller technique are used to form bilayers. In both methods, increasing the chl concentration produces greater photosensitivity. The photocurrent/area is about an order of magnitude higher in bilayers formed with the solvent free method, under similar conditions. From the quantum yield calculations, it appears that the higher photocurrent/area obtained with the Montal‐Mueller membranes cannot be explained solely due to the greater concentration of pigment molecules in the solvent free system. The possible role of chl—chl interactions are considered.

A tribute to Seymour Steven Brody: in memoriam (November 29, 1927 to May 25, 2010)

“…We found that the photocurrent/area was about an order of magnitude higher in bilayers formed with the solvent-free method. From quantum yield calculations, it appeared that the higher photocurrent/area obtained with the Montal-Mueller membranes could not be explained solely due to the greater concentration of pigment molecules in the solvent-free system, thus suggesting a possible role of chlorophyll-chlorophyll interactions (Rich and Brody 1981). We went on to study the effects that various carotenoids played on increasing electron transfer in the solvent-free bilayers and discovered that the dihydroxy carotenoids were significantly more efficient in electron transfer than beta carotene (Rich and Brody 1982).…”