Abstract: Metal nanoclusters have received much attention due to their excellent fluorescence properties. In this paper, the detection of nickel ions using a dual-emission fluorescent nanoprobe (His-Ag NCs@DHLA-Ag NCs) consisting of two silver nanoclusters (Ag NCs) was explored. This probe showed two emission peaks at 476 nm and 661 nm, respectively, under 365 nm excitation. After the introduction of nickel ions, the fluorescence intensity at 661 nm was significantly reduced, while the fluorescence at 476 nm remained basically unchanged. The specific and sensitivity detection of nickel ions by His-Ag NCs@DHLA-Ag NCs could be realized by comparing the intensities of the two peaks, and the detection limit was 67.3 nmol/L. The ability to detect nickel ions in tap water and lake water was verified by the spiked recovery test, and the spiked recoveries ranged from 92.00% to 103.67% with the relative standard deviations between 2.17% and 4.62%, indicating that the dual-emission fluorescent nanoprobe had a good prospect for the detection of nickel ions in water samples.
Keywords: fluorescence; silver nanoclusters; dual emission; nickel ions; detection