Development of liposomal immunosensor for the measurement of insulin with femtomole detection.

The monitoring of insulin is of great relevance for the management of diabetes, the detection of pancreatic islet-cell malfunction, the definition of hypoglycemia, and the diagnosis of insulinoma. A liposomal immunosensing system for the determination of insulin was developed in this study. The insulin sensor was constructed by the immobilization of anti-insulin antibodies on the inner wall of the microcapillary immunoseparator.

Application of ganglioside-sensitized liposomes in a flow injection immunoanalytical system for the determination of cholera toxin.

Cholera, an acute infectious disease associated with water and seafood contamination, is caused by the bacterium Vibrio cholerae, which lives and colonizes in the small intestine and secretes cholera toxin (CT), a causative agent for diarrhea in humans. Based on earlier lateral flow assays, a flow injection liposome immunoanalysis (FILIA) system with excellent sensitivity was developed in this study for the determination of CT at zeptomole levels. Ganglioside (GM1), found to have specific affinity toward CT, was inserted into the phospholipid bilayer during the liposome synthesis.

Electrochemical immunosensor for cholera toxin using liposomes and poly(3,4-ethylenedioxythiophene)-coated carbon nanotubes.

A sensitive method for the detection of cholera toxin (CT) using an electrochemical immunosensor with liposomic magnification followed by adsorptive square-wave stripping voltammetry is described. Potassium ferrocyanide-encapsulated and ganglioside (GM1)-functionalized liposomes act as highly specific recognition labels for the amplified detection of cholera toxin. The sensing interface consists of monoclonal antibody against the B subunit of CT that is linked to poly(3,4-ethylenedioxythiophene) coated on Nafion-supported multiwalled carbon nanotube caste film on a glassy carbon electrode.

Application of a liposomal bioluminescent label in the development of a flow injection immunoanalytical system.

A flow injection liposome immunoanalytical system was developed using biotin as the model analyte and liposomal aequorin as the label. Aequorin is a photoprotein isolated from luminescent jellyfish (notably Aequorea victoria) and other marine organisms that emits visible light in the presence of a trace of Ca2+. Because of this characteristic, the aequorin complex has been used as an intracellular Ca2+ indicator.

Liposome-based microcapillary immunosensor for detection of Escherichia coli O157:H7.

Our group has previously reported a sandwich-based strip immunoassay for rapid detection of Escherichia coli O157:H7 [Anal. Chem. 75 (2003) 4330].