Rhodamine 6G and Au�Pd core�shell nanorods: fluorescence enhancement for detection of mercury

Abstract

We show that hybrid organic-inorganic particles are efficient for accurate sensing of mercury ions and following up trace amounts of the mercury pollutions spread in the environment.The process of synthesis of a working substance starts from preparation of rhodamine 6G derivative.Then the dye molecules are bound on the surface of Au-Pd core-shell nanorods.Mercury ions with different concentrations are finally attached onto this fluorescence sensor.Fluorescence emission of the sensor is detected with a luminescence spectrophotometer.The experimental results demonstrate that the fluorescence intensity of one of our sensors, a sensor B, is remarkably enhanced when the mercury-ion concentration increases from 0 to 15.5 µM.The limit of detection of the ions is as low as 20.6 nM.The working mechanism of our fluorescence sensor can be explained through the fluorescence-energy transfer and the plasmonic effect associated with spirolactam forms of rhodamine and conducting bimetallic nanoparticles.