Green-Emissive Copper Nanocluster with Aggregation-Enhanced Emission for Selective Detection of Al3+

Graphical Green-emissive copper nanoclusters (Cu NCs) were synthesized at a relatively high reaction temperature (80 °C) and an extended reaction time to 144 h. The photoluminescence of Cu NCs could be selectively enhanced by adding Al 3+ , attributed to their aggregation-enhanced emission features. Selective detection of Al 3+ is of great significance both for the benefit of human health and environmental safety considerations. In this work, a sensitive and selective fluorescence assay for Al 3+ was proposed based on the green-emissive Cu nanoclusters (Cu NCs). Different from the commonly reported works, the green emissive Cu NCs showed dual emission bands at 450 and 510 nm, attributed to the reaction product between polyvinyl pyrrolidone and ascorbic acid and the Cu core, respectively. Al 3+ could induce the aggregation of Cu NCs by forming covalent bonds, which results in the enhancement of photoluminescence intensity. This enhancement phenomenon is rather selective to Al 3+ , which endows the detection in real samples. These results provide new insights for the fluorescence mechanisms of metal NCs, which also provided a functional luminescent material for various applications, such as chemical sensing, bioimaging and photoelectric devices.