Surface Charge Redistribution-Induced Electrochemiluminescence Enhancement of Gold Nanoclusters: The Novel Generation of Efficient Illuminants

Herein, we developed the agmatine/6-aza-2-thiothymine templated gold nanoclusters (Agm/ATT-Au NCs) as a novel electrochemiluminescence (ECL) illuminant, which exhibited high ECL in the annihilation path via the newly defined surface charge redistribution-induced ECL enhancement (SCRIE). Impressively, the electrochemical redox reaction of Agm/ATT-Au NCs was enhanced owing to the boosted electron transfer kinetics of the illuminant by the positively charged Agm-triggered surface charge redistribution of ATT-Au NCs, resulting in an ∼110-fold higher ECL signal of Agm/ATT-Au NCs than ATT-Au NCs. This work digs deep into the electrogenerated process of the annihilation mechanism to direct the rational design of an efficient illuminant. Moreover, the Agm/ATT-Au NCs as a powerful illuminant was successfully applied in a highly sensitive bioassay platform for detecting glial fibrillary acidic protein (GFAP) with the detection limit down to 27.5 ag/mL, an intense organic light-emitting diode (OLED), and high-definition ECL imaging.