Hexagonal Prism-Shaped\nAIE-Active MOFs as Coreactant-Free\nElectrochemiluminescence Luminophores Coupled with Hollow Cu<sub>2–<i>x</i></sub>O@Pd Heterostructures as Efficient Quenching Probes\nfor Sensitive Biosensing

For most self-luminous metal–organic framework\n(MOF)-involved\nelectrochemiluminescence (ECL) systems, the integration of exogenous\ncoreactants is indispensable to promote ECL efficiency. However, the\nintroduction of a coreactant into an electrolyte would result in poor\nstability, thereby inevitably affecting analytical accuracy. Herein,\nby employing aggregation-induced emission luminogens as ligands, we\nfirst synthesized one hexagonal prism-shaped MOF that displays robust\nand steady ECL signal without an exogenous coreactant. Furthermore,\nadenosine triphosphate (ATP), as the target analyte, can be fixed\non the electrode surface directly owing to the strong coordination\nbetween Zr<sup>4+</sup> and phosphate groups. According to the ECL\nresonance energy transfer effect, hollow Cu<sub>2–<i>x</i></sub>O@Pd heterostructures are conveniently prepared and act as\nefficient quenching probes. Remarkably, the resultant urchin-like\nhollow structure could provide more active sites to anchor ATP aptamers,\nthus enhancing the ECL quenching efficiency. In this manner, an elaborate\ncoreactant-free ECL system was developed to detect ATP, which demonstrates\na remarkable detection limit of 0.17 nM, as well as excellent stability\nand reproducibility. The present work offers significant enlightenment\nfor the further evolution of advanced ECL systems integrated with\nMOF-based luminophores.