An “off–on” colorimetric chemosensor for selective detection of Al3+, Cr3+ and Fe3+: Its application in molecular logic gate

Abstract

A novel Schiff base receptor (E)-1-(4-((4-(diethylamino)-2-hydroxybenzylidene)amino)phenyl)-3,4-diphenyl-1H-pyrrole-2,5-dione (BASB) was synthesized and characterized. The receptor BASB exhibited a selective “off–on” recognition toward Al3+, Cr3+ and Fe3+ among the various tested metal ions. It showed significant color change from colorless to yellow, with the appearance of a new charge transfer absorption band at 425nm. The detection limits for Al3+, Cr3+ and Fe3+ were found to be 2.16×10−6M, 1.27×10−8M and 5.03×10−8M, respectively. The binding stoichiometry between BASB and Al3+ was observed to be 2:1 whereas, Cr3+and Fe3+ showed 1:1 binding stoichiometry based on the Job's plot analysis. Further, a Boolean type molecular logic gate system of BASB was developed in the presence of Al3+ and F− as chemical inputs.