Biosensors avidin-biotin systems

In 1989, to the best of our knowledge, the first report appeared on the use of an avidin-biotin system for the immobilization of enzymes in the preparation of biosensors. Walt et al. have immobilized biotin-modified enzymes (urease, esterase, and penicillinase) on the surface of biotin-modified optical fiber using avidin as a binder (Figure 5a). They have demonstrated the general use of this procedure in immobilizing several types of enzymes. At nearly the same time, Gunaratna and Wilson used an enzyme column in which choline esterase and choline oxidase were immobilized through avidin-biotin complexation for the determination of acetyl-... 

Chen, Q., Kobayashi, Y., Tekeshita, H., Hoshi, T., Anzai, J. (1998). Avidin-biotin system-based enzyme multilayer membranes for biosensor applications optimization of loading of choline esterase and choline oxidase in the hienzyme membrane for acetylcholine biosensors. Electroanalysis 10 94-7. 

Large differences between the interfacial properties of ds and ssDNAs observed earlier by capacitance measurements [10, 37] suggested that a.c. impedance measurements could be used to detect DNA hybridization on electrodes [433, 434] (Sect. 12.8.). A three-component ODN system on a gold electrode (involving avidin-biotin interactions) was used to detect specific DNA sequences by means of faradaic impedance spectroscopy [435]. Impedance spectroscopy does not seem, however, to be the most convenient method for the DNA biosensor faster and simpler voltam-metric or chronopotentiometric methods will probably be more convenient. Gon-ductivity of the perfect DNA, contrasting with a loss of conductivity in duplexes with mismatched bases, may be of use in... 

The binding affinity between streptavidin and biotin is among the strongest noncovalent bonds known to exist (A o = 10" M) Therefore, the high affinity coupling of the biotin-avidin system has been used to immobilize different biomolecules on the surface of biomaterials and biosensors. " - It consists of using avidin as a bridge between the biotinylated surface and biotinylated... 

---