Multicolor saccharide-sensing chips based on boronic acid-containing thin films showing stepwise release and binding of dyes.

A novel saccharide sensor that shows a distinct color change resembling a "traffic signal" was developed. By copolymerizing a boronic acid monomer and an amine monomer on a glass plate, a boronic acid-containing thin film was obtained. After adsorbing anionic blue and yellow dyes, the thin film was immersed in aqueous saccharide solutions containing a cationic red dye.

Colorimetric sensing method for polyamines utilising an inclusion complex of stimuli-responsive amylose.

Incorporation of carboxyl groups into amylose led to a unique stimuli-responsive supramolecular system that shows distinct colour change in response to biologically important polyamines. When spermine was added to an aqueous solution containing iodine and amylose modified with carboxyl groups, the solution clearly changed from colourless to bluish purple. This colour change was attributed to the encapsulation of iodine into the helical cavity of amylose, which was triggered by the electrostatic association between the amylose and spermine.