A new possibility of using variations in the permeability of liquid membran
es for sensing cholesterol in aqueous media has been explored. The method i
s based on the enhancement of conductance of the lecithin-prostaglandin and
lecithin-nystatin liquid membrane bilayers due to the formation of hydroph
ilic pathways by the addition of cholesterol. Since enzyme is not used, the
stability of the device is not governed by the stability of the enzyme. Th
e response time of the device is less than 60 s. The device using prostagla
ndin has been tested by estimating free cholesterol in blood serum and it w
orks well. (C) 2000 Elsevier Science B.V. All rights reserved.