Although many measures have been taken to prevent contamination, pollutants, such as mercury and lead, can still end up in the environment. Mercury can be harmful if consumed through contaminated water or food.
Rapid on-site detection of hazardous chemicals is imperative for remote security and environmental monitoring applications. However, the implementation of current sensing technologies in real environments is limited due to an external high-power requirement, poor selectivity, and sensitivity.
Now, researchers at Taiwan’s National Tsing Hua University, led by Prof. Zong-Hong Lin, have developed an innovative self-powered nanosensor that can discover small amounts of mercury ions simply by touching a sample and immediately report the result.
The new sensor utilizes a natural phenomenon called the triboelectric effect – a form of static electricity. This generated electricity keeps the device running, and also its voltage can be used to signal the presence of a particular analyte.
More specifically, researchers used an array of mercury-sensitive tellurium nanowires to fabricate their triboelectric nanosensors (TENS). This made the sensor highly selective, allowing it to pick out its target even in complicated samples.
To test their self-powered nanosensor, the team mounted the device onto the fingertips of a robotic hand and repeatedly touched it into a sample solution. The change in voltage was wirelessly transmitted to a smartphone in real-time, corresponding to the presence or absence of mercury ions.
The robotic sensor also successfully detected ions in both naturally sourced and tap water with the same tapping method. It also detected them in food, including a shrimp and an apple, after they had been spiked with the contaminant.
According to the researchers, their nanosensors could serve as the basis for similar devices to monitor other pollutants remotely and safely.
- Snigdha Roy Barman, Yu-Jhen Lin, Kuan-Ming Lee, Arnab Pal, Naveen Tiwari, Sangmin Lee, and Zong-Hong Lin. Triboelectric Nanosensor Integrated with Robotic Platform for Self-Powered Detection of Chemical Analytes. ACS Nano 2023, DOI: 10.1021/acsnano.2c10770