Fluorescent Sensor for Copper(II) and Cyanide Ions via the Complexation-Decomplexation Mechanism with Di(bissulfonamido)spirobifluorene

Komthep Silpcharu; Siraporn Soonthonhut; Mongkol Sukwattanasinitt; Paitoon Rashatasakhon

doi:10.1021/acsomega.1c02744

Fluorescent Sensor for Copper(II) and Cyanide Ions via the Complexation-Decomplexation Mechanism with Di(bissulfonamido)spirobifluorene

ACS Omega. 2021 Jun 17;6(25):16696-16703. doi: 10.1021/acsomega.1c02744. eCollection 2021 Jun 29.

Authors

Komthep Silpcharu¹, Siraporn Soonthonhut¹, Mongkol Sukwattanasinitt^{1

2}, Paitoon Rashatasakhon^{1

2}

Affiliations

¹ Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
² Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.

Abstract

A novel spirobifluorene derivative bearing two bissulfonamido groups is successfully synthesized by Sonogashira coupling. This compound exhibits a strong fluorescence quenching by Cu(II) ion in a 50% mixture between acetonitrile and 20 mM pH 7.0 N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid (HEPES) buffer with a detection limit of 98.2 nM. However, this sensor also shows ratiometric signal shifts from blue to yellow in the presence of Zn(II), Pb(II), and Hg(II) ions. The static quenching mechanism is verified by the signal reversibility using ethylenediaminetetraacetic acid (EDTA) and the Stern-Volmer plots at varying temperatures. The Cu(II)-spirobifluorene complex shows a highly selective fluorescence enhancement upon the addition of CN^- ion with the detection limit of 390 nM. The application of this complex for quantitative analysis of spiked CN^- ion in real water samples resulted in good recoveries.