Visual detection of cysteine and homocysteine.

The determination of cysteine and homocysteine levels is of great current interest for the monitoring of desease states. A new colorimetric method for the simultaneous detection of l-cysteine and l-homocysteine has been developed. A fluorescein derivative reacts with the above amino acids, producing their respective thiazolidines resulting in color changes.

Postcolumn HPLC detection of mono- and oligosaccharides with a chemosensor.

Novel chromophoric compound 1 promotes the HPLC postcolumn detection of mono- and oligosaccharides. The detection of chromatographic peaks in the visible region for glucose, fructose, maltodextrins, sialic acid, and a ganglioside can be accomplished with a standard UV-vis detector. The use of selective, reversible binding agents in automated HPLC assays should allow for improved monitoring of specific analytes as well as material recovery.

Chromophore formation in resorcinarene solutions and the visual detection of mono- and oligosaccharides.

The colorimetric properties of resorcinarene solutions had not been investigated since Baeyer's initial synthesis. We recently reported that solutions containing resorcinarene macrocycles develop color upon heating or standing. In the presence of saccharides, these solutions exhibit significant color changes which are easily seen.