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Thick, Oriented and Selective Antibody Immobilization on the Surface of Optical Transducers with the Use of Self-assembled Layer and Specific Receptors

Nickolaj F. Starodub 

Ukrainian National Academy of Sciences, A. V. Palladin Institute of Biochemistry, 9 Leontovicha, Kyiv 01030, Ukraine

Abstract

In the report some theoretical aspects and the experimental results about treatment of transducer surface and the use of self-assembled layer and specific receptors for immobilization of Ab are presented. It was shown that the layer of polyelectrolites self-assembled (PESA) provides higher (~10 times) specific signal of SPR and planar polarization interferometry immune sensors in comparison with that when their surfaces were not treated (bare gold) or treated by glutaraldehyde (silicon nitride) or by dodecanthiol. It is result of increase of the density of recognizing elements on the surface. Staphylococcal protein A and lectins allow to structure and to orient Ab toward solution due to the presence of specific binding site for them in second C-domain of Ig. Different types of Ab have an unequal affinity to the individual lectins. The effective thickness of immobilized Ab increases in series: bare surface, treated by or PESA and contained PESA with protein A or some lectins. The higher layer is observed at the formation of IgG-anti-IgG complex since IgG surface has a great number of Ag determinants. The thickness of anti-IgG-IgG layer is near to that observed for IgG-anti-IgG if protein A or lectins were introduced into PESA. It testifies that F(ab)2 fragments are oriented towards solution. The use of some lectins instead of protein A as intermediate layer for the Ab immobilization allows us to obtain more high sensitivity of the determination of such low weight toxins as 2,4-D, simasine and nonylphenol. This phenomenon is analysed in term of density of recognising sites on the surface and their free orientation. The glycolysated protein of jp51 may be selective immobilized from mixture of retroviral proteins (p24 and jp51) if it is necessary to discriminate ill animals and preliminary immunized ones by vaccines with p24protein. The overall scheme of effective Ab immobilisation on the optical transducer surface is given on the basis of obtained result summation.

 

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Related papers

Presentation: Keynote lecture at SMCBS 2003 Workshop, by Nickolaj F. Starodub
See On-line Journal of SMCBS 2003 Workshop

Submitted: 2003-08-14 15:06
Revised:   2009-06-08 12:55