Electrochemical transduction of the interactions of the sweeteners acesulfame-K, saccharin and cyclamate with bilayer lipid membranes (BLMs)

摘要

This work explores the interactions of the sweeteners acesulfame-K, saccharin and cyclamate with bilayer lipid membranes (BLMs). BLMs composed of egg phosphatidylcholine (PC) can be used for the direct electrochemical sensing of these sweeteners. The interactions of these compounds with lipid membranes were found to be electrochemically transduced in the form of a transient current signal with a duration of seconds, which reproducibly appeared within 11 s after exposure of the membranes to the sweetener. The mechanism of signal generation was investigated by differential scanning calorimetric studies and monolayer compression techniques. These latter studies revealed that the adsorption of sweeteners caused an increase of the average molecular area occupied by the lipids, and resulted in increased structural order of membranes. The alteration of lipid density can change the 'effective area' of the headgroup and the orientation/association of water, and therefore the electrostatic fields at the surface of the membranes. The magnitude of the transient current signal was related to the concentration of the sweetener in bulk solution in the micromolar range. The potential interferences of the present electrochemical transduction were investigated. The present technique can be used as a one shot sensor for the rapid detection of these sweeteners.