Fabrication of stable solid fluorescent starch materials based on Hantzsch reaction

In this paper, a series of fluorescent starches were prepared simply and effectively by Hantzsch multi-component reaction (MRC). These materials showed bright fluorescence emission. Notably, due to the existence of poly-saccharide skeleton, starch molecules can effectively inhibit the common aggregation induced quenching effect caused by the aggregation of conjugated molecules in traditional organic fluorescent materials. Meanwhile, the stability of this material is so excellent that the fluorescence emission of the dried starch derivatives would not destroy after boiling at a high temperature in some common solvents, and even brighter fluorescence can be stimulated in alkaline solution. In addition to fluorescence, starch was also endowed with hydrophobic property by one-pot method connecting long alkyl chains. Compared with native starch, the contact angle of fluorescent hydrophobic starch increased from 29 degrees to 134 degrees. Furthermore, the fluorescent starch can be prepared into film, gel and coating by different processing methods. The preparation of these Hantzsch fluorescent starch materials provide a new way for the functional modification of starch materials and has great application potential in detecting, anti-counterfeiting, security printing and other related fields.

Automated summary

A series of fluorescent starches were prepared using Hantzsch multi-component reaction (MRC), exhibiting bright fluorescence emission. The poly-saccharide skeleton effectively inhibited aggregation-induced quenching effect seen in traditional organic fluorescent materials. The starch derivatives showed excellent stability, maintaining fluorescence emission even after boiling and displaying brighter fluorescence in alkaline solutions. Additionally, the starch acquired hydrophobic properties by connecting long alkyl chains, and it can be processed into film, gel, and coating. These fluorescent starch materials provide a new approach for functional modification of starch and have great application potential in various fields like detection, anti-counterfeiting, and security printing.