A dual chemosensor for Zn2+ and Co2+ in aqueous media and living cells: Experimental and theoretical studies

A new versatile 'dual' chemosensor 1 has been synthesized for Zn2+ and Co2+. The sensor 1 comprises of quinoline as a fluorophore and N1,N1-dimethylethane-1,2-diamine as a water-soluble functional group. Sensor 1 showed a remarkable fluorescence enhancement in the presence of Zn2+ in aqueous solution. The sensor 1 also acted as a colorimetric sensor for Co2+ by changing its color from colorless to yellow. Importantly, the chemosensor 1 could be used to quantify Zn2+ and Co2+ in water samples and to image and quantify Zn2+ in living cells. Moreover, the sensing mechanisms of 1 for Zn2+ and Co2+ were supported by theoretical calculations. Therefore, this sensor has the ability to be a practical system for monitoring Zn2+ and Co2+ concentrations in biological systems and aqueous samples.