Simple method for detection of extremely diluted anti beta-casein antibodies from glass bead based receptors.

The current work describes the elaboration of a simple, sensitive and reliable β-casein modified glass beads, for the detection and quantification of its specific antibody anti β-casein. This is an elementary receptor without electronic part, developed by grafting glass bead surface with the antigenic β-casein via 3-aminopropyltriethoxy silane and then glutaraldehyde as cross-linker. The whole is realized by a classical process, called in two steps and in mild conditions where chemical protocol is optimized for β-casein use.

Urea potentiometric biosensor based on modified electrodes with urease immobilized on polyethylenimine films.

The development of a new electrochemical sensor consisting in a glass-sealed metal microelectrode coated by a polyethylenimine film is described. The use of polymers as the entrapping matrix for enzymes fulfils all the requirements expected for these materials without damaging the biological material. Since enzyme immobilization plays a fundamental role in the performance characteristics of enzymatic biosensors, we have tested four different protocols for enzyme immobilization to determine the most reliable one.