NEW FERROCENE-BASED FLUORESCENT CHEMOSENSOR

Abstract

Two new compounds containing a ferrocene unit as a well-behaved electron-donor and a naphthalimide moiety as a strongly fluorescent transducer are designed and successfully synthesized. The incorporation of a hydrophilic triethyleneglycol unit can enhance the water-solubility and facilitate the dispersion of compounds in aqueous media. The incorporation of the ferrocene unit in both compounds results in molecules with low quantum efficiencies due to the photoinduced electron transfer (PET) from ferrocenyl to naphthalimide moiety. However, one of these compounds exhibits a selective fluorescent turn-on by the addition of Au (III) ion or Au (I) with low to neglible interference by 10-fold concentration of analytes to other metal ions in PBS buffer/acetonitrile. The effect of water content towards the response time and the effect of pH on sensitivity also the effect of surfactants of this sensor are investigated. Under optimum conditions, the detection limit for Au (III) ion was 80 ppb.