A colorimetric sensor array for the rapid identification of benzylisoquinoline alkaloids and Coptidis Rhizoma based on urease inhibition

Abstract

Benzylisoquinoline alkaloids are significant phyto-nutraceuticals with a bitter flavor. However, due to their complex structures, the sensing and identification of benzylisoquinoline alkaloids is challenging. Benzylisoquinoline alkaloids are commonly extracted from plants such as Coptidis Rhizoma (CR), while the adulteration and dyeing of CR are prevalent. Herein, we innovatively developed a colorimetric sensor array based on the inhibitory effect of alkaloids on urease to identify benzylisoquinoline alkaloids and CR. Urea and pH indicators are used to convert the inhibitory effect of alkaloids on urease into visible signals. Different benzylisoquinoline alkaloids have different inhibition abilities to urease, resulting in their own unique colorimetric response pattern. Combined with linear discriminant analysis (LDA), the colorimetric sensor array has successfully identified different types and concentrations of benzylisoquinoline alkaloids, as well as benzylisoquinoline alkaloid mixtures. The array was further employed to identify CR, encompassing its authenticity, variety, adulteration, and dyeing.

Keywords: Benzylisoquinoline alkaloids; Colorimetric sensor array; Phytochemical identification; Urease inhibition.