Post-synthesis of Tb@Zn-MOF composite as a multi-emission sensor for efficient detection of DCNA

The widespread overuse of 2,6-dichloro-4-nitroaniline (DCNA) in agricultural production has resulted in dire ecological consequences. Designing and constructing metal-organic frameworks (MOFs) based luminescent sensors for highly sensitive, selective, and recyclable detection of DCNA is crucial for environmental sustainability. Herein, a multi-emission center Tb@Zn-MOF composite material was prepared via a post-synthesis modification (PSM) strategy using Zn-MOF as a carrier to incorporate with Tb³⁺. The Tb@Zn-MOF composite material exhibited good stability and multi-emission characteristics, making it an efficient luminescence sensor for the toxic pesticide substance DCNA. The incorporation of lanthanide ions into the vacancies of MOF successfully enlarged the emission range and increased the emission centers. The mechanism revealed that PET (photoinduced electron transfer) and energy absorption competition between DCNA and Tb@Zn-MOF leads to prominent luminescence quenching. Finally, the Tb@Zn-MOF sensor was immobilized onto a polyvinyl alcohol membrane, achieving a portable and convenient approach for DCNA detection.