Nanoconfinement Synergistic Self-Catalytic Coenhanced Electrochemiluminescence Sensors for Chloramphenicol Detection

Nanoconfinement strategy is an effective approach to solve the luminescence quenching of aggregation-induced emission (AIE) materials in dispersed states. However, conventional synthetic carriers mostly used excessive metal ions, resulting in significant defects in terms of biosafety. As a natural blood protein, hemoglobin (Hemo) exhibits excellent biocompatibility and contains Fe²⁺, which can be used as a catalyst for electrochemiluminescence (ECL) process. Therefore, a novel self-catalytic aggregation-induced electronuminescence (AIECL) probe based on the confinement of tetrakis(4-aminophenyl)ethene (ETTA) by Hemo has been developed. It overcomes the high cytotoxicity of conventional synthetic carriers. In this work, Hemo was used as a dual-functional nanoencapsulant, which had dual roles as a nanoconfinement carrier and co-reaction promoter. Its unique quaternary structure not only provided a stable self-assembly environment for the nanoconfinement, but also effectively inhibited the free diffusion of ETTA in solution, thereby inducing the AIECL of ETTA. Importantly, Fe²⁺ in Hemo could be used as co-reaction promoter to shorten the electron transfer pathway, while achieving self-catalytic and greatly enhancing the ECL performance of the luminophore. In addition, the coral-like Au structure could improve the conductivity and loading capacity of the electrode. The chloramphenicol sensor exhibited excellent detection performance with a low detection limit of 0.12 pM. This work provides new insight for constructing green and efficient biosafety probes, which have shown important application potential in the field of food safety testing.