Gramicidin A interaction at a dioleoyl phosphatidylcholine monolayer on a mercury drop electrode.
A biosensor where the sensing surface is a fluid dioleyl phosphatidylcholine monolayer (DOPC) deposited on a mercury drop was used. The lipid monolayer was held in 0.1 M NaCl and a concentration of gramicidin A in the range 0-12 nM was used. Electrochemical impedance spectroscopy in the frequency range 0.1-65 kHz was employed to investigate how the defect-free monolayer responds to interactions of gramicidin A in solution. The data was analyzed both with multivariate data analysis and classical electrochemical methods. The principal component analysis of the resulting impedance spectra gave a linear dependence on the concentration of gramicidin A. An increasing permittivity was observed in the low-frequency regime with increasing concentration of gramicidin A in solution.
Lindholm-Sethson
Britta
B
Department of Chemistry, Umeå University, Sweden. britta.sethson@chem.umu.se
Nyström
Josefina
J
Geladi
Paul
P
Nelson
Andrew
A
D015374:Biosensing Techniques / Q000379:methods*; D025802:Electric Capacitance; D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006096:Gramicidin / Q000032:analysis* / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008628:Mercury; D015999:Multivariate Analysis; D010713:Phosphatidylcholines / Q000737:chemistry*
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D006096:Gramicidin; C017251:1,2-oleoylphosphatidylcholine; D008628:Mercury