Tunable Inverse Opal Hydrogel pH Sensors

Abstract

The synthesis, swelling kinetics, and optical diffraction of inverse opal hydrogel sensors (see Figure) are demonstrated. Colloidal crystal templating is used to prepare methacrylate/acrylic acid (AA) copolymers that have an interconnected pore structure, allowing facile diffusion and a relatively rapid response. The system shows good mechanical stability and pH‐dependent shifts in optical diffraction regulated by the AA concentration.