Development of Colorimetric and Turn-On Fluorescence Sensor for the Detection of Al3+ and F- Ions: DNA Tracking and Practical Performance as Applications

In this study, a new probe is designed (E)-1-(((5-mercapto-1,3,4-thiadiazol-2-yl)imino)methyl)naphthalen-2-ol (NAATD) for dual colorimetric and turn-on fluorescence chemosensor. Higher selectivity and sensitivity towards Al3+/F- ions over other competitive ions in DMSO solution were achieved. The detection limits were found to be 3.14 nM and 9.9 nM for Al3+ and F- ions respectively. The sensing mechanism and stoichiometric ratio is investigated and affirmed by DFT calculations and Job's plot analysis respectively. The DNA tracking ability of the NAATD-Al3+ is investigated by fluorescence technique which indicates that DNA efficiently bind with the probe and displace Al3+ ions. Finally, the practical utility of the probe was successfully demonstrated by using environmental water and tooth paste samples.