A Wireless Sensor Based On 3-Mercaptopropyl Sulfonic Acid Membrane Modified Gold Electrode For Detection Of Hg2+

A novel wireless sensing device was designed by adopting remote controlling procedure through wireless electronic transmitting/receiving modules for acquiring potential data based on 3- mercaptopropanesulfonic acid (MPS) modified gold electrode, which could be applied to remote ultrasensitive monitoring of Hg2+. The surface properties of MPS membrane electrodes with Hg2+ combined and uncombined were characterized by means of SEM, XPS, electrochemical impedance spectroscopy and cyclic voltammetry, indicating that the MPS containing the terminal of sulfonic group exhibited good recognition interaction toward Hg2+ through electrostatic adsorption, which was due to the formation of double electric layer resulting in change of membrane potential. In Tris. HCl buffer solution (pH = 6. 0), the MPS membrane electrode had good linear relationship between potential response and Hg2+ concentration in the range of 1. 0 x 10(-8) - 1. 0. 10(-3) mol/L with a slope of 59. 08 mV/(-pC) (25 degrees C), and the detection limit was calculated to be 8. 31 nmol/L. In addition, the MPS. based wireless sensor displayed fast response time, i.e. 8 s, with good stability, reproducibility and selectivity. This method was successfully used for the determination of Hg2+ in real water samples with recovery of 93. 7% - 101. 9%, showing important application prospects in real. time monitoring of environmental water.