Fructose-stabilized DNA-copper nanoclusters as a nanoprobe for the one-pot fluorometric detection of mercury ions

Mercury ion (Hg2+) is a highly toxic environmental pollutant, particularly harmful to human health, necessitating the development of analytical techniques with advanced performance to monitor its presence. Herein, we demonstrate the utility of fructose-stabilized DNA-copper nanoclusters (Fru@DNA-CuNCs) as a stable nanoprobe for the sensitive detection of Hg2+ with a simplified procedure. Upon interaction with Hg2+, the fluorescence of Fru@DNA-CuNCs undergoes rapid quenching, which was caused by metallophilic interactions promoting electron transfer between Hg and Cu, changing the electron configuration of nanoclusters. This nanoprobe exhibits exceptional sensitivity, with a detection limit of 2.49 nM for Hg2+ detection, and the detection process costs less than 20 min. Importantly, unlike other unstable CuNCs analogs, the incorporation of fructose enhances the stability of the Fru@DNA-CuNCs, which can maintain its performance for Hg2+ detection after being stored for up to 4 weeks. This robustness makes it suitable for Hg2+ monitoring without specialized and centralized facilities. To our knowledge, this is the first attempt to explore the analytical application of Fru@DNA-CuNCs, providing a facile, rapid, and stable synthetic biology-based sensing technique for Hg2+ monitoring.