N-(3-Trifluoroethanesulfonyloxypropyl)anthraquinone- 2-carboxamide: a new heterobifunctional reagent for immobilization of biomolecules on a variety of polymer surfaces

A new heterobifunctional reagent, N-(3-trifluoroethanesulfonyloxypropyl)anthraquinone-2-carboxamide (NTPAC) has been developed, useful for making bioconjugates and immobilization of biomolecules, viz., oligonucleotides, peptides, proteins, etc., on a variety of carbon-containing solid surfaces. Its trifluoroethanesulfonate ester group reacts with aminoalkyl or mercaptoalkyl functions present in biomolecules, and the anthraquinone structure reacts with a variety of carbon-containing polymers under ultraviolet irradiation (365 nm). The reagent has been used in two ways. First, the reagent, NTPAC, was first brought in contact with the above said supports and exposed to long wavelength ultraviolet light (365 nm), thereby generating active trifluoroethanesulfonate ester functions on the support, which subsequently react with appropriate mercaptoalkyl- or aminoalkyl-containing biomolecules to fix them on the supports. In another route, the proposed reagent was allowed to react first with proteins or 5'-aminoalkyl- or mercaptoalkyl-modified oligonucleotides to form the appropriate biomolecule-anthraquinone conjugate, which was then brought in contact with a variety of carbon-containing polymers, viz., modified controlled pore glass (CPG), modified glass microslides, cross-linked polystyrene, nylon, cross-linked polysaccharides, polypropylene (PP), polyethylene (PE), etc., and exposed to long wavelength ultraviolet light (365 nm), resulting in immobilization of the conjugates on the support. Both of the routes work satisfactorily and we could successfully immobilize a number of enzymes and modified oligonucleotides on a variety of supports.