CRISPR/Cas12a-Mediated Aptasensor Based on Tris-(8-hydroxyquinoline)aluminum Microcrystals with Crystallization-Induced Enhanced Electrochemiluminescence for Acetamiprid Analysis.

Improving the electrochemiluminescence (ECL) efficiency of luminophores has always been the goal of the ECL field. Herein, a novel crystallization-induced enhanced ECL (CIE ECL) strategy was exploited to significantly enhance the ECL efficiency of metal complex tris-(8-hydroxyquinoline)aluminum (Alq 3 ). Alq 3 monomers self-assembled and directionally grew to form Alq 3 microcrystals (Alq 3 MCs) in the presence of sodium dodecyl sulfate. The highly ordered crystal structure of Alq 3 MCs not only constrained the intramolecular rotation of Alq 3 monomers to decrease nonradiative transition but also accelerated the electron transfer between Alq 3 MCs and coreactant tripropylamine to increase radiative transition, thus leading to a CIE ECL effect. Alq 3 MCs exhibited brilliant anode ECL emission, which was 210-fold stronger than that of Alq 3 monomers. The exceptional CIE ECL performance of Alq 3 MCs coupled the efficient trans-cleavage activity of CRISPR/Cas12a assisted by rolling circle amplification and catalytic hairpin assembly to fabricate a CRISPR/Cas12a-mediated aptasensor for acetamiprid (ACE) detection. The limit of detection was as low as 0.79 fM. This work not only innovatively exploited a CIE ECL strategy to enhance the ECL efficiency of metal complexes but also integrated CRISPR/Cas12a with a dual amplification strategy for the ultrasensitive monitoring of pesticides such as ACE.