Physics

Nanotechnology

Electrode

Electrochemiluminescence

Optics

Surface modification

Physical chemistry

Aqueous solution

Chemistry

Materials science

Nanoclusters

Photoluminescence

Monochromatic color

Optoelectronics

Photochemistry

Angewandte Chemie International Edition

Inspired by the enhanced photoluminescence of Au nanoclusters (AuNCs) with a rigid shell, the formation of rigid host–guest assemblies on AuNC surfaces was employed to screen novel electrochemiluminophores with 6‐aza‐2‐thiothymine(ATT)‐protected AuNCs (ATT‐AuNCs) and l ‐arginine (ARG) as models for the first time. The rigid host–guest assemblies formed between ARG and ATT on the ATT‐AuNC surface enabled aqueous‐soluble ARG/ATT‐AuNCs with a dramatically enhanced electrochemiluminescence (ECL) compared to ATT‐AuNCs. This includes one cathodic ECL process (−1.30 V) and three anodic ECL processes (+0.78, 0.90, and 1.05 V) in a so‐called half‐scan experiment without a co‐reactant, as well as a 70‐fold enhanced oxidative‐reduction ECL at +0.78 V with tri‐n‐propylamine as a co‐reactant. Importantly, the ECL of the ARG/ATT‐AuNCs is highly monochromatic with an emission maximum around 532 nm and a full width at half‐maximum of 36 nm, which is of great interest for color‐selective ECL assays.

Efficient and Monochromatic Electrochemiluminescence of Aqueous‐Soluble Au Nanoclusters via Host–Guest Recognition