Detection of mercury(II) ion in water using an organic field effect transistor with a cysteine immobilized gold electrode
In this note, we report on the electrical detection of a mercury(II) ion (Hg2+ in water using an organic field effect transistor (OFET) The fabricated OFET device possesses an extended gate gold electrode functionalized with l cysteine (known as a Hg2+ ligand) We have investigated the detection ability of the OFET by immersing the extended gate electrode in an aqueous solution with various Hg2+ concentrations. As a result, we have successfully observed the decrease in the drain current of the OFET upon the addition of incremental amounts of Hg2+ in water. The limit of detection for Hg2+ in this device is estimated to be 31 ppb.