MemSens: a new detection method for heavy metals based on silver nanoparticle assisted memristive switching principle

This work reports a new heavy metal sensing and detection methodology based on memristive switching effect. The hysteresis loop and limiting linear characteristic of a memristive device are used to validate the hypothesis of detection of heavy metals by putting them in contact with silver nanoparticles (Ag NPs). The sensing of various heavy metal ions using the proposed methodology was done and the results showed a response towards all tested metal ions. In particular, the selectivity of the Ag NPs towards Cd²⁺ ions was more than other metal ions. The current against concentration graph for Ag NPs + Cd²⁺ ions system was obtained which gives the possibility of determination of Cd²⁺ ion concentration in an unknown sample. The concentration of the Cd²⁺ ions was varied to test the lower limit of detection of the system and found that the sensor system was able to detect the Cd²⁺ up to very low concentration. Therefore, the conceptually new heavy metal detection approach is a significant new advancement in heavy metal detection and preparation of portable devices for that purpose.