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

Improving the electrochemiluminescence (ECL) efficiencyof luminophoreshas always been the goal of the ECL field. Herein, a novel crystallization-inducedenhanced ECL (CIE ECL) strategy was exploited to significantly enhancethe ECL efficiency of metal complex tris-(8-hydroxyquinoline)aluminum(Alq(3)). Alq(3) monomers self-assembled and directionallygrew to form Alq(3) microcrystals (Alq(3) MCs) inthe presence of sodium dodecyl sulfate. The highly ordered crystalstructure of Alq(3) MCs not only constrained the intramolecularrotation of Alq(3) monomers to decrease nonradiative transitionbut 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 brilliantanode 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/Cas12aassisted by rolling circle amplification and catalytic hairpin assemblyto fabricate a CRISPR/Cas12a-mediated aptasensor for acetamiprid (ACE)detection. The limit of detection was as low as 0.79 fM. This worknot only innovatively exploited a CIE ECL strategy to enhance theECL efficiency of metal complexes but also integrated CRISPR/Cas12awith a dual amplification strategy for the ultrasensitive monitoringof pesticides such as ACE.

Automated summary

A novel crystallization-induced enhanced ECL strategy was developed to enhance the ECL efficiency of metal complex tris-(8-hydroxyquinoline)aluminum (Alq(3)). The Alq(3) microcrystals (Alq(3) MCs) showed significantly stronger ECL emission compared to Alq(3) monomers. This work not only innovatively improved the ECL efficiency of metal complexes but also integrated CRISPR/Cas12a with a dual amplification strategy for ultrasensitive pesticide monitoring.