Synthesis of highly stable fluorescent poly(methacrylic acid- co -itaconic)-protected silver nanoclusters and sensitive detection of Cu 2 .

Stable fluorescent silver nanoclusters (AgNCs) were synthesized through one-step UV photoreduction using the multiple carboxyl copolymer poly(methacrylic acid- co -itaconic acid) P(MAA- co -IA) as a novel template. The fluorescence lifetime and the quantum yield of the obtained AgNCs were 1.84 ns and 8.9% in an aqueous solution, respectively. Owing to the multiple carboxyls of the protective P(MAA- co -IA) template, the obtained AgNCs have excellent advantages such as good dispersity, and high stability, which make them suitable for highly sensitive and selective detection of Cu 2+ by fluorescence quenching. A good linear relationship exists between the degree of fluorescence quenching for silver nanoclusters and Cu 2+ concentration ranging from 0 to 10 μM. The limit of detection (LOD) is 6.36 nM. The result implies that the as-synthesized AgNCs show great potential in the analysis field.