Ciprofloxacin as chemosensor for simultaneous recognition of Al3+ and Cu2+ by Logic Gates supported fluorescence: Application to bio-imaging for living cells

Abstract

Simultaneous high sensitivity detection of metal ions is important for research in medicine, living cells and environmental samples. In this work, the antibiotic ciprofloxacin (Cipro) is used as a chemosensor for the simultaneous detection of Al3+ and Cu2+ by fluorescent assisted logic gates. The interference of common coexisting metal ions such as Cd2+, Ni2+, Cu2+, Sr2+, Mg2+, Co2+, Fe3+, K+, Al3+, Sm3+, Ag+, Na+, Ba2+, Cr3+, Zn2+, Bi3+ and Mn2+ was tested, and no interference with the simultaneous detection of Al3+ and Cu2+ was found. Interestingly, the fluorescence intensity quenches for Cu2+ and enhances for Al3+ with the increasing concentration of Cipro, showing that it acts as fluorescence-OFF and -ON, respectively; however, with a sequential addition of Cu2+ to Cipro, followed by Al3+, the fluorescence intensity greatly increases, becoming the fluorescence-ON mode. Other combinations of metal ions addition to Cipro do not change the fluorescence behavior. Importantly, the detection of Al3+and Cu2+ in the real samples like living cells was carried out, and it was found that Cipro efficiently performs as fluorescent probe for Al3+ ion in living systems, especially in Saccharomyces cerevisiae; this is confirmed by confocal laser scanning microscopy.