New strategy endowing natural nutriment curcumin provides smart fluorescence for anti-counterfeiting

Stimuli-responsive fluorescent hydrogels (FHs) are excellent and attractive candidates for information encryption and anti-counterfeiting applications, which can allow the stored information to be visualized by a vibrant display with a higher degree of security levels. However, hydrogel-based information storage devices for anti-counterfeiting are still in their infancy that developing an environment-friendly, low-cost, and scalable approach to produce stimuli-responsive FHs is still challenging.

Curcumin is a natural biocompatible and sustainable material, which has shown great therapeutic potential as an anti-diabetic, anti-inflammatory, and anti-cancer compound and has been used in our daily lives serving as nutriment. Although it is a pH-sensitive and fluorescent molecule, it is difficult to use in the hydrogels as fluorescent agent due to its very weak fluorescence in polar water.

A study published in the KeAi journal Green Chemical Engineering, has introduced a new strategy to construct strong fluorescent hydrogels using curcumin as fluorescent agent. The curcumin was loaded in to an amphiphilic quaternary ammonium (QA) micelle, which endow the hydrogels with excellent mechanical properties and both pH-responsive color and fluorescence to provide a dual anti-counterfeiting capability. This facile scalable method for fabricating the pH-FHs shows great potential for producing materials for information encryption and anti-counterfeiting applications.

Co-corresponding author Xiubin Xu, from the School of Chemistry and Chemical Engineering of Guangzhou University in China, explains: “Compared to conventional fluorescenct agents, curcumin is natural, biocompatible, and sustainable, which is meaningful and intersting to facilitate its scalable application, such as anti-counterfeiting. As a result, we were able to obtain fluorescent hydrogels using the curcumin as fluorescent agents, which shows good mechanical properties, good anti-fatigue performance, and smart fluorescence responding to ammonia gas and formaldehyde gas. The hydrogels also exhibit information storage-rewriting behavior and dual anti-counterfeiting capabilities. We believe that these strategies and achievements can facilitate the design of robust and smart FHs for information encryption and anti-counterfeiting applications.”