Protein-confinement synergizes with aggregation-induced-emission enhancement strategy for tetracycline detection

Spatial confinement strategy presents a novel approach to addressing the luminescence quenching of aggregation-induced-emission (AIE) materials in solution. However, traditional synthetic carriers suffer from batch-to-batch variability and poor biocompatibility. A novel aggregation-induced-electrochemiluminescence (AIECL) probe with core-shell structure was developed based on natural nanocavities of ovalbumin (OVA) as a biocompatible carrier through molecular self-assembly. This strategy innovatively integrates protein confinement with AIECL, effectively suppressing the luminescence quenching of tetrakis(4-aminophenyl)ethene (ETTA) in solution and significantly enhancing electrochemiluminescence (ECL) performance. Furthermore, OVA confinement offered multiple advantages: OVA provided dual-confinement through covalent bonds and hydrophobic interactions that enhanced the stability and ECL intensity of OVA/ETTA; OVA improved the aqueous solubility of ETTA while mitigating its cytotoxicity; the mild synthesis conditions without high temperature or pressure significantly reduced energy consumption; OVA provided active sites for aptamer (Apt) conjugation. The introduction of the coreaction promoter further enhanced the ECL responses of the aptasensor, enabling precise detection of tetracycline in the range of 0.1 pM∼1 μM with a detection limit of 42.6 fM. This strategy not only expands the application of food proteins in AIECL sensing but also adheres to Green Chemistry principles and provides new insights into the development of an environmentally-friendly, and low-energy-consumption ECL analysis platform.