Photobonding of Biomolecules for Biochip Manufacturing

Abstract

Immobilization of biomolecules on material surfaces while retaining their biological functions is a major challenge in biochip manufacturing. Photobonding is a unique procedure for bioprobe immobilization on “inert” surfaces by a light-induced process. We have designed and synthesised photolinker polymers carrying several photoactivatable chemical functional groups (e.g. aryldiazirines). When irradiated with light, the photoactivatable chemical groups turn into reactive intermediates. Generated intermediates bond to all neighboring materials that are either substrate or biomolecule. In biochip technology, hydrophilic polysaccharides (or bovine serum albumin) are appreciated as molecular barriers due to their biological inertness and biocompatibility.

In this study dextran was modified with photoactivatable groups. The product, OptoDex, served as the basis for the syntheseis of several photoactivatable OptoDex analogues. Photolinker polymer mediated covalent immobilization of bio-molecules was attained under mild and non-invasive conditions. Neither reactive functional groups on the biomolecule nor on the material surface were required to achieve single step probe molecule immobilization. The described photobonding process combines several unique properties: local addressability, light-dependent covalent bonding, single-step multicompent immobilization and chemical multi-functionality through modification of the parent molecules. The construction of biochip microarrays was achieved by combining ink-jet printing and photobonding technologies.