Determination of the distance law of the transfer of electronic excitation energy
In a frequently applied method the exponent, n, of the distance R, of interacting molecules, appearing in the expression of the efficiency, f, of transfer, is determined from the slope of a straight line obtained by plotting In ( f −1 −1) vs. In c c 0 ( c and c 0 are the concentration of the solutio...
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Published in | Journal of theoretical biology Vol. 86; no. 4; pp. 663 - 671 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Ltd
01.01.1980
|
Online Access | Get full text |
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Summary: | In a frequently applied method the exponent,
n, of the distance
R, of interacting molecules, appearing in the expression of the efficiency,
f, of transfer, is determined from the slope of a straight line obtained by plotting In (
f
−1 −1) vs. In
c
c
0
(
c and
c
0 are the concentration of the solution and a constant critical concentration characteristic of the interacting molecules and their environment, as defined in the Förster theory of transfer). The dependence of
f on
c is usually determined experimentally from the concentration quenching of fluorescence. From the theoretical quenching curve and the analytical expression for the slope, it is concluded that In (
f
−1 −1) vs. In
c
c
0
is not strictly linear, but a curve with slopes yielding exponents from
n = −6−
n = −3, in contrast to the fact that the interaction theoretically remains very weak (with
n = −6). A correct exponent is obtained experimentally from the high-concentration part of the quenching curve or by using the theoretical dependence of the slope on the concentration in the case of very weak interactions. For strong interactions, In (
f
−1 −1) vs. In
c
c
0
is linear, and
n = −3 in the whole concentration range. However,
f is slightly volume-dependent. |
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ISSN: | 0022-5193 1095-8541 |
DOI: | 10.1016/0022-5193(80)90305-7 |