Characterization of a label system formed by large unilamellar vesicles for its potential use in the design of electrochemical biosensors

Abstract

In this contribution a new electrochemical label system formed by DOPC/palmitic acid/cholesterol/sucrose large unilamellar vesicles (LUVs) with K4(Fe(CN)6) encapsulated is described and, characterized by using electrochemical techniques, dynamic light scattering (DLS) and transmission electron microscopy (TEM). Results indicates that incorporation of cholesterol to the membrane promote a meaningful reduction in the loss of the encapsulated electroactive molecu1le. On the other hand, the addition of sucrose allows a successful lyophilization process, and confers stability to the system over long periods of time, remaining unchanged even for ten months after being formed. These properties make this system a very stable label that could be linked to an antibody, antigen or DNA strain; after the specific interaction with the analyte, LUVs rupture can be induced and the electroactive molecule encapsulated can be released and electrochemically detected by using square wave voltammetry. These characteristics make this new system into a signal amplifier that can be used to replace traditional enzyme-labels in electrochemical biosensors design.