Thin-Film Polyisocyanide-Based Hydrogels for Affinity\nBiosensors

Abstract

A new type of hydrogel\nthin film that can be post-modified with\nbiofunctional molecules is investigated for possible applications\nin evanescent wave optical affinity biosensors. This material is based\non a polyisocyanide (PIC) copolymer that self-assembles into a fibrous\npolymer network. It is covalently tethered to a solid transducer surface,\nand its swelling gives rise to a hydrogel layer with a thickness up\nto several micrometers, as characterized by a combination of surface\nplasmon resonance and optical waveguide spectroscopy. Thin PIC-based\nhydrogel films with pendant functional biomolecules can be used in\nlabel-free affinity sensing strategies. In this work, we demonstrate\nthe PIC-based affinity binding matrix through an avidin coupling of\nfunctional biomolecules and immunoassay-based detection, which can\nbe readily expanded to other types of assays and target analytes.\nIn addition, the stable PIC matrix proves to be resistant to fouling,\neven in the presence of complex biological fluids such as blood plasma\nor serum.