Electrochemiluminescence covalent organic framework coupling with CRISPR/Cas12a-mediated biosensor for pesticide residue detection

The trace detection of pesticide residue becomes particularly important since increasing attentions have been attached to food safety. Herein, we developed an electrochemiluminescence (ECL) covalent organic framework (COF) based-biosensor for trace pesticide detection coupling with CRISPR/Cas12a-mediated signal accumulation strategy. Firstly, the target conversion was carried out with an aptamer-assembled magnetic spherical nucleic acids, which can convert acetamiprid to activator DNA, triggering the CRISPR/Cas12a to make quenching probes far away from electrode for signal accumulation. The COF with stable and strong ECL was synthesized by a condensation reaction between the perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and melamine (MA), due to the highly ordered arrangement of the PTCDA luminescence units among COF structure and the pore confinement effect. Moreover, the designed assay method was successfully employed to detect the residual level of acetamiprid in real sample and expected to be widely used in pesticide-related food safety.