Ultrasensitive and rapid screening of mercury(II) ions by dual labeling colorimetric method in aqueous samples and applications in mercury-poisoned animal tissues

•Rapid and ultrasensitive screening of mercury ions are achieved by using gold nanoparticles based colorimetric method.•Dual labeling strategy is adopted for sensing signal amplification.•The proposed method is successfully used for analysis of mercury-poisoned animal tissues.

Rapid and ultrasensitive detection of trace heavy metal mercury(II) ions (Hg2+) are of significant importance due to the induced serious risks for environment and human health. This presented article reports the gold nanoparticle-based dual labeling colorimetric method (Dual-COLO) for ultrasensitive and rapid detection of Hg2+ using the specific thymine–Hg2+–thymine (T–Hg2+–T) as recognition system and the dual labeling strategy for signal amplification. Both qualitative and quantitative detections of Hg2+ are achieved successfully in aqueous samples. More importantly, the achieved detection limit of 0.005 ng mL−1 (0.025 nM) without any instruments is very competitive to other rapid detection methods even ICP-MS based methods. This Dual-COLO method is also applied directly for real water sample monitoring and, more importantly, applied in analysis of mercury poisoned animal tissues and body fluidic samples, indicating a potentially powerful and promising tool for environmental monitoring and food safety control.

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