Sensitive and selective detection of nitrite ions with highly fluorescent glutathione-stabilized copper nanoclusters

In this work, we demonstrated a facile green method for the preparation of fluorescent copper nanoclusters (Cu NCs) with a high quantum yield of 8.6%, using glutathione as the stabilizing agent and ascorbic acid as the reductant. The as-prepared Cu NCs had good water solubility and ultrafine sizes. Further investigation revealed that the fluorescence of Cu NCs was linearly quenched by nitrite ions over the concentration range of 10–225 μM, with the detection limit of 3.4 μM. The proposed method has been successfully applied to determine nitrite ions in real water samples.