From one to three, modifications of sensing behavior with solvent system: DFT calculations and real-life application in detection of multianalytes (Cu2+, Ni2+ and Co2+) based on a colorimetric Schiff base probe

Abstract

A rhodamine-based colorimetric sensor, RBOV has been synthesized and modified for selective detection of Cu2+, Ni2+ and Co2+ ions simultaneously in aqueous medium. The difference in color change upon binding with these three cations makes it an interesting multianalyte sensor. Furthermore, the detection limits of RBOV for Cu2+, Ni2+ and Co2+ are down to 4.0 × 10−2 µM, 3.2 × 10−1 µM and 4.8 × 10−1 µM respectively. The possible sensing mechanism analyzed from Benesi-Hildebrand plot, Job's plot, FTIR and DFT studies showed a 1:1 stoichiometry of sensor-metal complex for all three analytes. Practical application of sensor was conducted in real time using test strips and MTT assay was conducted to determine its cytotoxicity.