Measurement of liposome-released ferrocyanide by a dual-function polymer modified electrode

Abstract

Potassium ferrocyanide Is encapsulated In the aqueous cavity of spherical phospholipid bilayer vesicles (liposomes) at concentrations of approximately 104 molecules/llposome. Physical parameters and stability of these structures are determined by electrochemical and spectroscopic methods. The electroactive marker Ions (ferrocyanide) are released from within the liposome by either the addition of surfactant or the complement lysis of the membrane. The classical complement pathway Is an antlgen/antlbody-speclflc reaction that occurs when an antigen-sensitized liposome Immunospeclflcally binds with a corresponding antibody In the presence of certain serum proteins (complement). The release of encapsulated ferrocyanide Is monitored by differential pulse voltammetry. Preliminary Investigations with an Ion-exchange polymer modified electrode demonstrate the ability to preconcentrate the released marker at the electrode surface as well as the necessity of a polymer film to protect the surface from fouling during serum-mediated lysis.

Sensitivity Enhancement of Leakage Current Microsensor for Detection of Target Protein by Using Protein Denaturant

“…The DPPC liposome entrapping a redox reagent, potassium ferrocyanide , was immobilized on the sensor in a intact manner. If the ion of is leaked from the DPPC liposome by a certain factor, the electron generated by the redox reaction of can be transferred to the anode [6]- [9]. The resulting current generated 1530-437X/$26.00 © 2011 IEEE by the electron transfer between the electrode surface and the solution is called as Faradic current.…”

An Alternative Approach to Quantify Partition Processes in Confined Environments: The Electrochemical Behavior of PRODAN in Unilamellar Vesicles

“…Therefore, the vesicles may contain both lipophilic and water-soluble substances. [2,3] Phospholipids form the fundamental matrix of natural membranes and represent the environment in which many proteins and enzymes display their activity. [4] Results obtained from small unilamellar vesicles (SUVs) are often controversially discussed as model systems for cells because of their small size and bilayer defects due to their high curvature.…”

“…[18] There are a few reports in which an electroactive molecule is encapsulated in the aqueous cavity of a vesicle and detected electrochemically upon lysis. [3,22,23] Very recently, Ikonen et al [24] applied an electrochemical method to determine the vesiclewater partition coefficients of several water-soluble b-blockers. Particularly, electrochemical studies at liquid/liquid interfaces are a good tool for the determination of the partition constant, since they allow the control of the interfacial potential and the ionic distribution of the two phases.…”

Adsorption of an Isocyanurate Silane on E-Glass Fibers from Ethanol and Toluene

“…Areas such as polymer-modified electrodes (24), polymer composites (25), and the covalent attachment of antibodies for affinity chromatography (26,27) have benefited from silane surface treatments. The most widely used coupling agents are the organosilanes, which improve the adhesion between the filler and the polymer matrix by interacting either chemically or physically with both the filler surface and the resin matrix.…”