Self-assembled block copolymer photonic crystal for selective fructose detection

The use of one-dimensional photonic crystals fabricated from a self-assembled lamellar block copolymer as a sensitive and selective fructose sensor is investigated. The polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) films are functionalized with 2-(bromomethyl)phenylboronic acid. The boronic acid moiety confined within the lamellar morphology can reversibly bind to sugars such as fructose, imparting the photonic properties of the PS-b-P2VP film. The films exhibit a detection limit of 500μM in water and 1mM in phosphate buffered saline. Exposure to a 50mM solution of fructose invokes a highly visible color change from blue to orange. The films are also able to selectively recognize and respond to fructose in competitive studies in the presence of glucose, mannose and sucrose. ► Self-assembled block copolymer photonic crystal was chemically modified with sugar sensing boronic acid functionality. ► When exposed to aqueous media the block copolymer photonic crystal swells reflecting visible wavelengths of light. ► Exposure to fructose concentrations invoked different color changing responses depending on the concentration. ► The color change is highly visible and can be determined without the use of an extraneous equipment. ► Fructose detection is maintained in interfering solutions containing ions or other sugars establishing selectivity.