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 (CoSA) and the ECL emitter MoS2 under mild conditions (not exceeding 200 °C). CoSA 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 S2O82-. 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@CoSA/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). CoSA/UiO-66 exhibits broad application prospects in improving ECL efficiency. MoS2@CoSA/UiO-66 builds a highly sensitive ECL sensing platform for detecting the biomarkers of AD and other diseases.