Gold nanoparticles and cleavage-based dual signal amplification for ultrasensitive detection of silver ions.

Silver ion (Ag(+)) is a highly toxic heavy metal ion to fungi, viruses, bacteria, and animals. Therefore, Ag(+) monitoring in water or food resources has become extraordinarily important within the scope of human health. Here, we report a gold nanoparticles and enzyme cleavage-based dual signal amplification strategy for ultrasensitive detection of Ag(+) using electrochemical techniques. This sensing platform for Ag(+) has an extremely low detection limit of 470 fM, which also has satisfactory selectivity. Thus, it can be directly used in drinking water and lake water samples. Moreover, the strategy proposed in this work may have potential to be further developed as a generalized platform for the detection of other analytes by designing new DNA sequences for specific recognition.