CuS@Ag Heterostructure-based Surface Plasmonic Coupling Electrochemiluminescence Sensor for Glioma miRNA-124-3p Detection.

As an emerging class of extended crystalline organic materials, covalent organic framework (COF)-based aggregation-induced emission luminogen (AIE-gen) exhibited encouraging emissive properties. In this work, 4',4'',4‴,4‴'-(1,1,2,2-Ethenetetrayl)tetra(4-biphenylcarbaldehyde) (ETBC) as AIEgen was used to prepare AIE-COF (ET-COF-COOH) luminescent nanoprobe. ETBC and 1,3,5-Tris(4-aminophenyl)benzene (TAPB) had an extended π electronic system that allowed electron delocalization and overlapping transport. Because AIEgen-ETBC served as the luminescence center of ET-COF-COOH, the ET-COF-COOH possessed an ideal anodic electrochemiluminescence (ECL) performance. Moreover, due to the surface plasmonic coupling (SPC) effect of the CuS@Ag square-cavity array, the ECL signal of ET-COF-COOH was amplified as 2.8 times. The AIE-COF/CuS@Ag SCH array-based SPC-ECL sensor was used to detect miRNA-124-3p with a wide range of 1 fM-10 nM and LOD of 0.49 fM. Furthermore, the proposed biosensor can effectively distinguish between tumor tissue and adjacent tissue and offer significant potential for advancing glioma diagnosis.