An easy-to-use platform for colorimetric determination of dextran: A potential application for the sugar industry

A user-friendly platform based on foam sheets and silica solid support was developed for colorimetric sensing of dextran via phenol–sulfuric acid assay. The chemical reagents, sulfuric acid and phenol were separately preserved by silica gel. The brown color product of the phenol–sulfuric acid reaction occurred on the silica solid support when sample solutions were added. The color intensity of brown products was easily obtained by a smartphone and color processing software. Subsequently, a broad concentration range of dextran could be determined up to 10,000 mg/L dextran, with a detection limit of 360 mg/L. Furthermore, a precision study, including inter-day and intra-day studies, presented a satisfactory performance for dextran detection. The developed platform was successfully applied for the sugar industry's dextran determination of syrup samples.