A novel fluorescent probe, carbon dots/gold nanoclusters (CDs/AuNCs), was prepared for ratiometric and colorimetric detection of Pb2+ and Hg2+ simultaneously. The as-prepared probe exhibited two distinct emission peaks at 445 nm and 610 nm. During the detection process, Pb2+ could quench blue fluorescence due to the formation of CDs-Pb2+ complex and do not affect orange fluorescence. Conversely, Hg2+ could quench the orange fluorescence greatly due to the Hg2+-Au+ metallophilic interaction and keep blue fluorescence unaffected. Accordingly, ratiometric fluorescence sensing approaches of Pb2+ and Hg2+ are achieved and dramatic color changes from pink to orange/blue can be observed under UV illumination upon the addition of Pb2+/Hg2+. Furthermore, good linear relationships between the fluorescence intensity ratio (I610/I445) and Pb2+/Hg2+ concentration were demonstrated in ranges of 0-130 nM for Pb2+ and 0 to 280 nM for Hg2+, with detection limits of 6.5 nM for Pb2+ and 3.7 nM for Hg2+, respectively. The probe showed excellent selectivity and the mutual interference problem of Pb2+ and Hg2+ coexist could be effectively solved by introducing masking agents. In addition, the application of CDs/AuNCs proved successful in detecting Pb2+ and Hg2+ in actual water samples, yielding satisfactory recovery rates. These results indicated that the probe provides a new approach for visualizing and semi-quantitatively detecting Pb2+ and Hg2+, making it highly promising for monitoring environmental water samples.

You have access to this article

Please wait while we load your content... Something went wrong. Try again?