18?-Glycyrrhetinic acid derivative-based metallo- hydrogels with highly selective and sensitive for histidine detection

Quantitative detection of His has aroused great interest in disease diagnosis since abnor-mal histidine (His) metabolism would cause a variety of serious diseases. However, exploiting a strategy with facile, highly selective, sensitive sensing and low-cost to monitor His remains a chal-lenge. In this study, a series of novel metallo-hydrogels were successfully constructed, which were composed of 18b-glycyrrhetinic acid (GA) derivative (GA-O-09) with rare earth metal ions (Ce3+, Tb3+, Eu3+ and La3+). In addition, these metallo-hydrogels possessed excellent thermody-namics stability with the gel melting temperature (Tgel) ranging from 62.4 +/- 0.49 degrees C to 67.4 +/- 0. 49 degrees C and remarkable pH stability over a range of pH values of 3-10. Interestingly, the Histidine (His)-loaded GA-O-09/Eu3+ hydrogel and the His-loaded GA-O-09/La3+ hydrogel displayed extraordinary fluorescence enhancement, in which the lowest fluorescence response concentrations (LODs) of the His-loaded GA-O-09/Eu3+ hydrogel and the His-loaded GA-O-09/La3+ hydrogel were 1.14 x 10-8 and 1.07 x 10-8 M, respectively. Therefore, the result showed that the study of the GA-O-09/Eu3+ and GA-O-09/La3+ hydrogels could provide a potential application for highly selective and sensitive detection for His.(c) 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, a series of novel metallo-hydrogels composed of GA-O-09 derivative (GA-O-09) with rare earth metal ions (Ce3+, Tb3+, Eu3+ and La3+) were successfully constructed. These metallo-hydrogels exhibited excellent thermodynamic stability and pH stability, and showed remarkable fluorescence enhancement in detecting histidine (His), providing a potential application for highly selective and sensitive detection of His.