Biosensor Array of Interpenetrating Polymer Network with Photonic Film Templated from Reactive Cholesteric Liquid Crystal and Enzyme‐Immobilized Hydrogel Polymer

Abstract A biosensor array is fabricated using an interpenetrating polymer network consisting of photonic film templated from reactive cholesteric liquid crystal (CLC) and enzyme‐immobilized polyacrylic acid (PAA). The solid‐state photonic film on the glass substrate is successfully templated by ultraviolet (UV) curing of the reactive CLC mixture of a reactive mesogen mixture of RMM 727 (from Merck) and a nonreactive chiral dopant of ( S )‐4‐cyano‐4′‐(2‐methylbutyl)biphenyl following the extraction of the chiral dopant. The acrylic acid monomer mixed with a cross‐linker of tri(propylene glycol) diacrylate is infiltrated into the extracted space of the photonic film, and UV‐cured with a photomask to obtain a patterned array‐dot film. The interpenetrated cholesteric liquid crystal/hydrogel polymer network (CLC‐hydrogel‐IPN) array is further functionalized in the individual dots with urease, for a model study of biosensor array applications. The dots of the CLC‐hydrogel‐IPN array respond independently to the urea by a color change with high sensitivity and stability. Thus, the patterned CLC‐hydrogel‐IPN can be used as a new biosensor array for cost‐effective and easy visual detection without any sophisticated instruments.