A self-powered mercury ion nanosensor based on the thermoelectric effect and chemical transformation mechanism

Self-powered sensors and sensing systems without an external power supply have shown their superior advantages and become more popular in recent years. In this paper, the first self-powered nanosensor based on the thermoelectric effect for the detection of mercury ions is demonstrated. In this sensing device, tellurium nanowires (Te NWs) act as the core material to spontaneously generate an electric output by a small surrounding temperature difference and act as a recognition element for specific reaction with mercury ions. The as-developed thermoelectric nanosensor can provide a high sensitivity (LOD of 1.7 nM) and good linear range (from 10 nM to 1 mu M) of mercury ion detection. The selectivity of the self-powered thermoelectric nanosensor is also evaluated. Among the investigated metal ions, only Hg2+ ions result in a distinct enhanced output voltage, by approximately 9 times. The self-powered thermoelectric sensor exhibits the capability to clearly distinguish even a small concentration of Hg2+ ions from the presence of various other species in environmental samples. All these results indicate that the thermoelectric nanosensor shows great potential to become a portable sensor for the in-field sensing of environmental samples.