1690-Fold Enhanced Electrochemiluminescence of Gold Nanoclusters via Zn2+ Induced Aggregation

Abstract

Herein, a zinc ion (Zn²⁺)-induced aggregation strategy is proposed for 1690-fold enhanced electrochemiluminescence (ECL) from D-penicillamine (DPA)-capped gold nanoclusters (AuNCs), the aggregation induced ECL (AIECL) is a multiplicative effect of two enhancing factors. One is the improved ligand rigidification of Zn²⁺-induced aggregation of AuNCs, i.e. Zn²⁺-AuNCs. The Zn²⁺ of Zn²⁺-AuNCs can reduce the vibration and rotation of DPA, suppress non-radiative decay, and bring out ~17-fold enhanced emission with photoluminescence (PL) as control. The other is the promoted electron transfer by Zn²⁺-DPA bonds, which can enhance charge annihilation with the assistance of energy level alignment between AuNCs and Zn²⁺-DPA bond, and further multiply ECL for another ~100-fold. The dual-enhanced AIECL strategy can be utilized to design even brighter ECL luminophores.