An off-on fluorescence sensor based on hydrogen-bonded organic frameworks for the detection of glutathione

Hydrogen-bonded organic frameworks (HOFs) have drawn great attention in recent years; however, few reports show the applications of HOFs in biosensing. Abnormal concentration of glutathione (GSH) usually relates to some diseases, thus quantifying the amount of GSH is of great importance. Fluorescence method has the advantages of high sensitivity, simplicity, and low cost, however, traditional fluorescent sensors for GSH need complex synthesis procedures for fluorescent probes. Herein, a simple off-on fluorescence sensor based on hydrogen-bonded organic frameworks (HOF-PyTTA) was constructed. Firstly, the fluorescence of HOF-PyTTA was quenched by Fe3+, and after the addition of GSH, Fe3+ reacted with GSH to restore the fluorescence intensity of HOF-PyTTA. Based on the above principles, a simple HOF-PyTTA/Fe3+ mixed system was constructed and applied to detect GSH. The concentration of GSH showed a good linear relationship with the fluorescent intensity of HOF-PyTTA/Fe3+ in the range of 0-0.40 mmol/L, and the limit of detection was 8.8 mu mol/L. This method was applied to the determination of GSH in human serum samples. The recoveries were in the range of 95.9-102.5 %, and the RSD was 0.1 % -0.64 %. The proposed method based on the off-on fluorescence change of HOF-PyTTA shows a simple operation and a rapid response within 10 min. It not only broadened the application of hydrogen-bonded organic frameworks but also indicated a great potential of HOF as an efficient fluorescence probe for biosensing.