P-33 Investigation into the mechanism of copper(II) ions sensing using dimethylaminocyanostilbene fluorescence

Copper(II) ions are selective quenchers of dimethylaminocyanostilbene (DCS) fluorescence over other metal ions even in a complex aqueous solution. This interaction provides a mechanism for developing a copper(II) ion sensor based on the fluorescence diminishment which could be used by individuals or businesses to do a quick screen of their drinking water to determine if the copper(II) ion concentration is above EPA actionable levels (1.3 ppm), especially if this technology can be integrated into a dip-strip device. The purpose of this research is to discover and understand the binding interaction between DCS and copper(II) ions to provide further insights in developing a robust and predictable sensing element. We have been able to show that DCS is able to easily detect copper(II) ions to 1.3 ppm using fluorescence quenching in an acetonitrile solution with a laboratory fluorescence spectrometer. Our investigation of pH, interfering ions, binding strength, and the development of molecular analogs of DCS have helped elucidate the details behind the specific fluorescence quenching mechanism in this copper(II) ion sensor