Valinomycin, solution preparation

Ding et al. have reported [95] a novel potassium ion sensor based on valinomycin-incorporated bilayers supported on a gold electrode modified by a hexadecylmercaptan monolayer. The ion selectivity for K+ is 400 times greater than for Na. The system is stable for two months at -10 °C which is much more practical than the reported stability of many cationic bilayer membranes with longevities of less than 120 hrs [113]. The lipid membrane is prepared by the painted-frozen method [114] in which the SAM modified electrode is coated with the lipid solution and allowed to freeze (removing the solvent) the supported bilayers are then immersed into a solution of valinomycin to create the K+ sensor. 

In a system developed by Cortese et al. [10], vesicles encapsulating actin were prepared by injecting diethyl ether dissolving phosphatidylcholine (PC) and phos-phatidylethanolamine together with a potassium ionophore, valinomycin, into a solution containing 48 pM monomeric actin. During the injection period (less than 5 min), the temperature was maintained at 52-55°C. The vesicle size was around 2-20 pm. After the dilution of actin outside the vesicles at least 10 times, the... 

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