Qatar University, Qatar
pp. 336 - 339
Keywords: graphene, nanoparticle, sensor, mercury
In this work we present a highly sensitive and selective sensor for detection of mercury traces in water. The sensor is constructed by creating interdigitated metal electrodes on a graphene layer placed on SiO2/Si substrate. Nanoparticles were generated by sputtering and inert gas condensation inside an ultra-high vacuum system, and they were deposited on top of the graphene layer with the metal electrodes. The nanoparticles used in this work are Gold (Au), Platinum (Pt) and Silver (Ag) because of their strong affinity to mercury. The sensor was tested by measuring the change in the electrical resistance of the sensor against different concentrations of Hg+2. The results demonstrate that the sensor can detect very low concentration of Hg+2 (as low as 0.05ppb) which is much below the guideline value from World Health Organization (WHO). The selectivity of the fabricated sensor was tested by measuring the response signal of the sensor against other heavy metals ions such as Cr(NO3)3, CdCl2 , CuSO4 , CoCl2 , Fe3(SO3)3 , ZnCl2 and Kl. The results prove that the fabricated sensor exhibit excellent selectivity to Hg+2 ions. The fabricated sensor is functional at room temperature, and it has low power requirement.