In the present study, highly sensitive and high-throughput optical waveguide biosensors were fabricated by using the sensing membranes containing dye and polymer-enzyme complex. Optical light waveguide can detect the optical change in the vicinity of the guide surface with high sensitivity due to the evanescent wave scattering. The glucose sensing membranes, composed of dye, enzymes, and biocompatible polymers were prepared by solution processing on the optical waveguide. Herein, we used 3, 3’, 5, 5’-tetramethylbenzidine (TMBZ) as a dye, glucose oxidase (GOD) and peroxidase (POD) as enzymes, phosphatide polymer for protection of biological activity of enzyme, and carboxymethyl cellulose (CMC) as a binder. Then we focused on the optimal composition and structure of sensing membranes for the enhancement in the sensitivity and response speed. The developed glucose sensors demonstrated 20 times higher sensitivity than the conventional light waveguide glucose sensors and the low-detection limit of 0.1g/L glucose within the detection time of 60 sec. For further improvement in the sensitivity, microporous sensing membranes were fabricated by using electrospraying technique. The electroprayed sensing membranes gave 40 % higher sensitivity than nonporous sensing membranes. These results show that both the composition and structure of sensing membrane are crucial factors for highly sensitive and high-throughput optical waveguide biosensors.

The effect of dietary conjugated linoleic acid (CLA) isomers mixture on antibody titres against sheep blood erythrocytes (SRBC) and immunoglobulin (Ig) G concentration in plasma was studied in broiler chickens. In experiment 1, male and female broiler chicks (11 d of age, Cobb strain) were fed a diet supplemented with 10 g CLA or 10 g safflower-seed oil/kg diet for 2 weeks. An SRBC suspension (5:100, v/v) in a phosphate buffer was intravenously injected at 18 d of age and a blood sample was taken from the wing vein at 25 d of age. Chicks fed the CLA-supplemented diet had enhanced first antibody titres in plasma to SRBC as compared with those fed the safflower-seed oil-supplemented diet, irrespective of sex differences. In experiment 2, male broiler chicks (8 d of age, Ross strain) were fed a basal diet or a diet containing 10 g CLA/kg diet for 3 weeks. CLA in the CLA diet partially replaced the soyabean oil in the basal diet. The SRBC suspension was intravenously injected at 15 and 25 d of age and a blood sample was obtained at 21 and 29 d of age. The first antibody titres against SRBC were higher in chicks fed the CLA diet than those in chicks fed the basal diet, but the second titres were not. Plasma IgG concentrations in chicks fed the CLA diet were higher than those in chicks fed the basal diet on both sampling days. The results showed that dietary CLA enhanced antibody production in broiler chickens.