Use of nanohybrid materials as electrochemical transducers for mercury sensors

The electrochemical behavior of mercury using different nanostructured screen-printed transducers has been studied. The first underpotential deposition (UPD) was chosen as the best electrodic process to detect low amounts of mercury on gold nanostructured electrodes. Several nanostructured electrochemical transducers using carbon nanotubes, graphene oxide and gold nanoparticles were generated, characterized and optimized for mercury determination in water. The transducer with a nanohybrid surface of carbon nanotubes and gold nanoparticles was the best suited to solve the analytical problem. For this sensor, a calibration plot from 0.5 to 50 μg/L was obtained in acidic solutions of Hg(II) with an intraelectrodic reproducibility of 3% (n = 5). The detection limit was 0.2 μg/L of mercury. The performance of the sensor was then evaluated using real samples of tap and river water with good accuracy.