Single-atom co anchored UiO-66 to boost electrochemiluminescence of MoS₂ for bioanalysis

Single-atom catalysts (SACs) hold significant promise for improving the electrochemiluminescence (ECL) efficiency. However, the preparation of SACs reported in the ECL field usually relies on carbon-nitrogen-based materials as substrates and requires high-temperature pyrolysis (>800 °C), suffering from the limitation in the anchoring materials and the deficiency of insufficient active site density caused by high-temperature calcination. This work developed zirconium-based metal-organic framework UiO-66 as the carrier to successively anchor the Co single-atom (Co_SA) and the ECL emitter MoS₂ under mild conditions (not exceeding 200 °C). Co_SA not only can optimize the electronic structure of MoS₂ to effectively promote the formation of Co(IV)=O, but also can act as the co-reactant accelerator to efficiently catalyze the reduction of coreactant S₂O₈^2-. Meanwhile, the Mo-O-Zr bimetallic sites formed between UiO-66 and MoS₂ can enhance the charge carrier mobility within MoS₂. As a result, the ECL emission of MoS₂ at -1.6 V was remarkably boosted when using step pulse as the electrochemical method. The synthesized MoS₂@Co_SA/UiO-66 composite integrated an aptamer recognition-driven cascaded polymerase amplification to achieve ultrasensitive ECL detection of p-Tau as crucial biomarker for Alzheimer's disease (AD). Co_SA/UiO-66 exhibits broad application prospects in improving ECL efficiency. MoS₂@Co_SA/UiO-66 builds a highly sensitive ECL sensing platform for detecting the biomarkers of AD and other diseases.