Ligand‐induced Assembly of Copper Nanoclusters with Enhanced Electrochemical Excitation and Radiative Transition for Electrochemiluminescence**

Abstract

Copper nanoclusters (CuNCs) are emerging electrochemiluminescence (ECL) emitters with unique molecule‐like electronic structures, high abundance, and low cost. However, the synthesis of CuNCs with high ECL efficiency and stability in a scalable manner remains challenging. Here, we report a facile gram‐scale approach for preparing self‐assembled CuNCs (CuNCsAssy) induced by ligands with exceptionally boosted anodic ECL and stability. Compared to the disordered aggregates that are inactive in ECL, the CuNCsAssy shows a record anodic ECL efficiency for CuNCs (10 %, wavelength‐corrected, relative to Ru(bpy)3Cl2/tripropylamine). Mechanism studies revealed the unusual dual functions of ligands in simultaneously facilitating electrochemical excitation and radiative transition. Moreover, the assembly addressed the limitation of poor stability of conventional CuNCs. As a proof of concept, an ECL biosensor for alkaline phosphatase detection was successfully constructed with an ultralow limit of detection of 8.1×10−6 U/L.

Coupled Poly(ethylenimine) Coreactant to Enhance Electrochemiluminescence of Polymer Dots for Array Imaging of Protein Biomarkers

“…The higher oxidation current of PEI/Pdots-modified GCE in PBS than that of Pdots-modified GCE in PBS containing PEI (Figure 2B, curve c) was indicative of more effective electron transport. 35 These results demonstrated that the shortened electron transfer distance between the emitter and coreactant helped to enhance ECL emission. 36 As expected, after covalently coupling PEI to Pdots to further shorten the electron-transfer distance and accelerate the electron transfer efficiency, 27 the PEI−Pdots modified GCE showed the highest ECL intensity (10 692 au) and oxidation current (Figure 2A,B, curves d).…”

“…When encompassing the PFBT Pdots surface with equivalent PEI via electrostatic interaction (denoted as PEI/Pdots), the ECL intensity of PEI/Pdots-modified GCE in PBS (1468 au) was higher than that of PFBT Pdots-modified GCE in the presence of equal amounts of PEI in PBS (Figure A, curves a and c). The higher oxidation current of PEI/Pdots-modified GCE in PBS than that of Pdots-modified GCE in PBS containing PEI (Figure B, curve c) was indicative of more effective electron transport . These results demonstrated that the shortened electron transfer distance between the emitter and coreactant helped to enhance ECL emission .…”

Supramolecular assembly-induced electrochemiluminescence enhancement of gold nanoclusters for hemoglobin detection

“…[15][16][17][18][19] Luminophores play an important role in ECL, and a variety of ECL luminophores, including ruthenium, luminol, nanoclusters, quantum dots, and others have been developed. [20][21][22][23][24][25][26] Among them, gold nanoclusters (Au NCs), composed of several to hundreds of gold atoms less than 3 nm in diameter, have great potential as excellent ECL luminophores because of their excellent optical properties, unique catalytic activity, and good biocompatibility. [27][28][29] However, the low efficiency and poor stability of Au NCs significantly hinder their practical applications.…”

Ultrasensitive Electrochemiluminescence Biosensor Based on Efficient Signal Amplification of Copper Nanoclusters Induced by CaMnO3 for CD44 Trace Detection

“…Nevertheless, the high cost of precious Me NCs greatly limits their application in ECL analysis. Therefore, it is especially significant to study the ECL performance and sensing applications of nonprecious Me NCs. − Recently, researchers have reported the self-assembled Cu NCs induced by ligands with exceptionally boosted anodic ECL . However, there is little research on the efficient cathode ECL emission of Cu NCs.…”