A convenient and rapid method for detecting d-glucose in honey used smartphone

[Display omitted] •The d-glucose dehydrogenase with His-tag was expressed in E. coli.•The color reaction system the enzyme catalyzed for detection of d-glucose was constructed.•Smart phone and Microsoft Photoshop was used for analyzing color.•The detection limit of the biosensor was 25 mM to 200 mM of d-glucose. Information concerning food composition, including information on its glucose content, is essential for modern food industry due to greater consumer awareness and expectations. In this work, the gene encoding d-glucose dehydrogenase (GDH) from Bacillus Natto was expressed in Escherichia coli BL21(DE3) firstly. Ni-IDA column was used for the purification of GDH. Then, the purified GDH was used to construct a color system with stable and effective measurement of concentration of d-glucose. The smart phone photographing and the software Microsoft Photoshop have been used in the system for determination of the color. The enzymatic analysis system can detect the concentration of d-glucose from 5 mM to 40 mM, and other various sugars has no interference to the system. The system was used to quantitatively detect the concentration of d-glucose in honey. The system can be used for convenient and rapid detection of d-glucose in food, especially for large numbers of samples.