Synthesis and Characterization of a Biotin-Alginate Conjugate and Its Application in a Biosensor Construction

Abstract

Biotin was covalently coupled with alginate in an aqueous-phase reaction by means of carbodiimide-mediated activation chemistry to provide a biotin-alginate conjugate for subsequent use in biosensor applications. The synthetic procedure was optimized with respect to pH of the reaction medium (pH 6.0), the degree of uronic acid activation (20%), and the order of addition of the reagents. The biotin-alginate conjugate was characterized by titration with 2-anilinonaphthalene-6-sulfonic acid (2,6-ANS), 4-hydroxyazobene-2'-carboxylic acid (HABA) and by an HPSEC-MALLS analytical method as well as by FTIR and 13C NMR spectroscopy. As a compromise between the need for a high percent of molar modification of the alginate, on one hand, and sufficient gelling capability, on the other hand, an optimal modification of 10-13% of biotin-alginate was used. The new biotin-alginate conjugate was used for the encapsulation of bioluminescent reporter cells into microspheres. A biosensor was prepared by conjugating these biotinylated alginate microspheres to the surface of a streptavidin-coated optical fiber, and the performance of the biosensor was demonstrated in the determination of the antibiotic, mitomycin C as a model toxin.

Advances in plant growth-promoting bacterial inoculant technology: formulations and practical perspectives (1998–2013)

“…This new immobilization material combines the advantages of alginate gelling properties to entrap cells providing them with a gentle hydrated and highly porous environment and the high affinity interaction of the avidin-biotin system. The conjugate was successfully used to encapsulate bioluminescent reporter cells into microspheres (Polyak et al 2004). (2) Alginate hydrogels can be reinforced at the surface with several secondary polymers to enhance their mechanical strength and stability to extend degradation time in soil, if needed (Bashan 1986a;Nussinovitch 2010).…”

Synthesis and characterization of a β-CD-alginate conjugate

“…However, a common side reaction that occurs when EDC is used is the internal rearrangement of the unstable O-acylisourea active ester into a stable N-acylurea. The latter not only precludes any nucleophilic attack of a primary amine on the carboxyl, but also is irreversibly grafted onto the polymer which may affect its properties [22]. Additionally, the amount of N-acylurea covalently grafted onto alginate increases with increasing EDC concentrations in the reaction medium, which does not allow to easily control the targeted degree of grafting of a molecule, even in the presence of N-hydroxysuccinimide (NHS) or its sulfonated derivative (Sulfo-NHS).…”

Controlled mechanical and swelling properties of urethane acrylate grafted calcium alginate hydrogels

“…SA has been largely employed in many areas, such as adsorbent [2], tissue engineering [3,4], food engineering, drug delivery [5,6], crop breeding, biosensor [7] and so on.…”