Patterned Photonic Array Based on an Intertwined Polymer Network Functionalized with a Nonenzymatic Moiety for the Visual Detection of Glucose.

A patterned photonic array chip based on an intertwined polymer network (IPN) is proposed for the visual detection of glucose. The IPN networks are composed of photonic and poly(acrylic acid) (PAA) networks. Aminophenylboronic acid, as a nonenzymatic glucose-responsive moiety that can covalently bond to glucose at alkaline pH, forming tetragonal complexes, is immobilized in the PAA network; in hydrogels, this bonding generates Donnan osmotic pressure, resulting in a volumetric increase of the photonic IPN and reflected color change. The photonic band gap wavelength linearly increases with the glucose concentration (in the 1-12 mM range), with a limit of detection of 0.35 mM. The dots of the photonic IPN array respond independently, with high sensitivity and stability, to glucose via color changes; different glucose levels, from hypo- to hyperglycemia, can be visually detected in this way. Serum samples spiked with different glucose concentrations were tested for practical evaluation of the chip. The proposed chip could be utilized as a new biosensor platform for cost-effective and easy visual detection in remote areas, without the need of advanced instruments or technology.