Frameworks-Enhanced Electrochemiluminescence in Biosensing

Electrochemiluminescence (ECL) has attracted increasing concerns owing to its intrinsic advantages of high sensitivity, good stability, and low background. Considering the fact that framework nanocrystals such as metal-organic frameworks and covalent organic frameworks have the accurate molecular structures, a series of frameworks-based ECL platforms are developed for decoding the emission fundamentals. The integration of fluorescent ligands into frameworks significantly improves the ECL properties due to the arrangement of molecules and intramolecular electron transfer. Moreover, the frameworks various topology can be easily functionalized with the recognition elements to trace the targets for signal readout. These ECL enhancement strategies lead to a series of sensitive analytical methods for protein biomarkers, DNA, small biomolecules, and cells. In this review, we have summarized recent advances in various functions of frameworks during ECL process, and constructions of frameworks-based ECL platforms for biosensing. The frameworks-based ECL nanoemitters and the enhancement mechanisms show both theoretical innovation and potential applications in designing ECL biosensing systems.