Rare earth hybrid materials based on hydrogen-bonded organic frameworks for luminescence response sensing applications

Abstract

This feature article summarizes recent advances in rare earth hybrid materials based on crystalline organic frameworks for luminescence responsive sensing applications, with a focus on rare earth hybrid materials based on hydrogen-bonded organic frameworks (REHM-HOFs). The evolution of the material system from amorphous to crystalline states is first outlined, highlighting the advantages of crystalline structures in terms of luminescence efficiency, stability, and tunability. The distinct features of HOFs, including mild synthesis conditions and structural diversity, are also emphasized. Subsequently, the review details the functionalization chemistry strategy of rare earth ions in crystalline organic frameworks, primarily based on post-synthetic modification (PSM), including coordination and ion exchange strategies. These strategies provide a chemical foundation for the precise anchoring of luminescent centers, the enhancement of energy transfer efficiency via the "antenna effect", and the modulation of luminescent response behaviors. Based on an in-depth analysis of their luminescence mechanisms and responsive modes, the paper highlights key advances of REHM-HOFs in photoresponsive applications, including: (i) anti-counterfeiting encryption; (ii) conventional sensing; (iii) intelligent detection; (iv) biomimetic applications under chemical stimuli; and (v) biomimetic applications under physical stimuli. Despite their great potential, REHM-HOFs still face challenges related to long-term stability, multifunctional integration, and translation to real-world applications. Future research should focus on novel material design, performance optimization, and integration with intelligent systems. Notably, this review highlights the innovative contributions of the authors' group, particularly the significant progress made in the practical application of REHM-HOFs.