Simple Colorimetric and Fluorescence Chemosensing Probe for Selective Detection of Sn Ions in an Aqueous Solution: Evaluation of the Novel Sensing Mechanism and Its Bioimaging Applications.

An easily accessible colorimetric and fluorescence probe 4-((3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-yl)amino)benzenesulfonamide () was successfully developed for the selective and sensitive detection of Sn in an aqueous solution. The sensing mechanism involves reduction of -C═O into -C-OH groups in upon the addition of Sn, which initiates the fluorescence turn-on mode. A better linear relationship was achieved between fluorescence intensity and Sn concentration in the range of 0-62.5 μM, with a detection limit (LOD) of 0.115 μM. The binding mechanism of for Sn was confirmed by Fourier transform infrared analysis, NMR titrations, and mass (electrospray ionization) spectral analysis. Likewise, the proposed sensing mechanism was supported by quantum chemical calculations. Moreover, bioimaging studies demonstrated that the chemosensing probe is an effective fluorescent marker for the detection of Sn in living cells and zebrafish. Significantly, was able to discriminate between Sn in human cancer cells and Sn in normal live cells.