Gold nanoclusters (AuNCs) are attractive electrochemiluminescence (ECL) emitters because of their excellent stability, near IR emission, and biocompatibility. However, their ECL quantum yield is relatively low, and our limited fundamental understanding has hindered rational improvement of this parameter. Herein, we report drastic enhancement of the ECL of ligand‐stabilized AuNCs by on‐electrode pre‐oxidation with triethylamine (TEA) as a co‐reactant. The l‐methionine‐stabilized AuNCs resulted in a record high ECL yield of 66 %. This strategy was successfully extended to other AuNCs, and it is more effective for ligand shells that allow more effective electron transfer. In addition, excitation of the pre‐oxidized ECL required a lower potential than conventional methods, and no additional instrument was required. This work opens avenues for solving a challenging problem of AuNC‐based ECL probes and enriches fundamental understanding, greatly broadening their potential applications.

Size-focusing results in highly photoluminescent sulfur quantum dots with a stable emission wavelength that can be used for bioanalysis.

Gold nanoclusters (AuNCs) are attractive electrochemiluminescence (ECL) emitters because of their excellent stability,n ear IR emission, and biocompatibility.H owever, their ECL quantum yield is relatively low,a nd our limited fundamental understanding has hindered rational improvement of this parameter.Herein, we report drastic enhancement of the ECL of ligand-stabilized AuNCs by on-electrode preoxidation with triethylamine (TEA) as ac o-reactant. The lmethionine-stabilized AuNCs resulted in ar ecordh igh ECL yield of 66 %. This strategy was successfully extended to other AuNCs,a nd it is more effective for ligand shells that allow more effective electron transfer.I na ddition, excitation of the pre-oxidized ECL required al ower potential than conventional methods,a nd no additional instrument was required. This work opens avenues for solving achallenging problem of AuNC-based ECL probes and enriches fundamental understanding,greatly broadening their potential applications.

composition. For this reason, over the past few years, numerous efforts have been made to design and prepare various types of all-inorganic halide perovskites. To date, most lead-containing perovskites tend to lose their structural integrity in the presence of moisture, oxygen, or light. [7] These stability issues have limited the applications of perovskite-based nanomaterials, such as photoelectrochemistry (PEC) and photocatalysis, especially in the aqueous phase. Besides, the toxicity of lead impedes their commercial applications. [8] Hence, elimination of lead from the prevailing halide perovskite and finding stable alternatives are in urgent need. [9] To obtain Pb-free ternary A 1 M 2+ X 3 halide perovskites, a simple method is to replace Pb 2+ with less toxic group IV metal ions like Sn 2+ or Ge 2+ , considering their similar electronic structure to Pb. [10] Unfortunately, the Sn 2+ / Ge 2+ halide perovskites are extremely unstable in the air and are perovskite frameworks easily oxidized to Sn 4+ /Ge 4+ , resulting in a poor performance when using optoelectronic devices. [11] Another options are lead-free quaternary A