Photoelectric measurements of s-BLM/nucleoli: a new technique for studying apoptosis

Immunosensor for trace penicillin G detection in milk based on supported bilayer lipid membrane modified with gold nanoparticles

In this work, we developed an immunosensor for electrochemical detection of penicillin G at trace level. The biosensor was fabricated by immobilizing anti-penicillin G in a supported bilayer lipid membrane (s-BLM) modified with gold nanoparticles, and the modified electrodes were characterized by the scanning electron microscope (SEM), cyclic voltammetry and electrochemical impedance spectroscopy. The biosensor was able to detect penicillin G with a linear correlation ranging from 3.34×10(-3)ng/L to 3.34×10(3)ng/L and a detection limit of 2.7×10(-4)ng/L, much lower than the maximum residue limit (MRL) of penicillin G in milk (4ppb, equal to 4×10(3)ng/L) set out by the European Union. The mean coefficient variation (CV) of the intra-assays and the inter-assays were 5.4% and 7.7%, respectively. In addition, the concentration of penicillin G in milk samples determined by this biosensor was in good agreement with that determined by high performance liquid chromatography (HPLC) assay.

Supported bilayer lipid membranes modified with a phosphate ionophore

This article reports the electrical responses of a phosphate ionophore, the cyclic polyamine 3-decyl-1,5,8-triazacyclodecane-2,4-dione (N3-cyclic amine) incorporated into metal supported bilayer lipid membranes (s-BLM). Teflon coated silver wire was used as a support. In a potentiometric mode, the ionophore had a response that was linearly related to the logarithm of HPO4(2-) concentration and was also dependant on pH. Selectivity coefficients for other anions compared to HPO4(2-) ions, determined by the separate solution method, fell within the range 1.73 x 10(-4) to 6.38 x 10(-2).

The 40th anniversary of bilayer lipid membrane research

This paper presents a historic perspective on the origin of the lipid bilayer concept and its experimental realization. Additionally, current studies in close collaboration with our colleagues on the use of supported BLMs as biosensors and molecular devices are delineated. Further, recent research of others on BLMs (planar lipid bilayers) is referenced.

Molecular recognition in a reconstituted tumor cell membrane

The design of an immunoliposome system for molecular recognition using reconstituted, hydrogel-supported bilayer lipid membranes (sb-BLMs) is described. By monitoring the electrical properties, two kinds of recognition are feasible: (i) the human bladder tumor cells, Ej and its antibody BDI-1, the lifetime of the reconstituted membrane is 42 min; and (ii) the human rectum tumor cells, LOVO, the life of the reconstructed membrane is more than 40 min, the same as conventional BLM. Further, the anticancer drug, Adriamycin (Anticancer Res., 20 (2000) 1391), was shown to be effective in such reconstituted systems, the life of which is less than 5 min. In these experiments, the active ingredients of the Ej and LOVO cells were determined on reconstituted sb-BLMs. The key point is that the component part being recognized on the BLM must be kept in its native state.

Fabrication and photoelectric properties of self-assembled bilayer lipid membranes on conducting glass

Supported bilayer lipid membranes (s-BLMs with and without the doping of fullerene C60) self-assembled on indium-tin oxide (ITO) glass were fabricated and characterized by cyclic voltammetry and electrochemical impedance spectroscopy using a three-electrode system. The photoelectric properties of the ITO supported planar lipid bilayers were studied. Light intensity of irradiation, bias voltage, and concentration of donors have been found to be limiting factors of the transmembrane photocurrent. The facilitation effect of C60 doping in s-BLMs on the photoinduced electron transfer across s-BLM is discussed. This novel self-assembled ITO/s-BLM system may provide a simple and mechanically stable model for the study of the photoelectric and photodynamic properties of biomembranes.