Application of a Rhodamine-chromone Schiff base probe for the sensing of Fe3+, Al3+, Cr3+at low concentration and exploration of the anticancer activity and bio-imaging

Strategic design of fluorescent probe for the recognition of ions/molecules at very low concentration by fluo-rescence sensing is one of the stimulating current research topics with reference to health and sustainability. Towards this objective, Rhodamine based chemosensors are playing extraordinary protagonist. In this work, a Rhodamine appended chromone Schiff base (RFC), with two fluorogenic motifs, has been characterized through various spectroscopic techniques. The probe exhibits efficient sensitivity towards Analytical Group IIIA ions (Al3+, Cr3+ and Fe3+) in existence of other competitive analytes. The fluorescent intensity is enhanced by 350 fold (Fe3+), 250 fold (Al3+) and 220 fold (Cr3+), respectively in methanol-water (99:1,v/v; HEPES buffer, pH, 7.2) medium. The limits of detection (LOD) (3 sigma/M method; sigma = standard deviation; M = slope) are 0.0051 ppm (Fe3+), 0.0029 ppm (Al3+) and 0.0052 ppm (Cr3+); which are impressive and much below the WHO recom-mended data. In addition to this, the compound has been utilized for cell imaging in presence of these three cations. The action of probe on MCF-7 (human breast cancer) cell lines demonstrates IC50, 2.53 mu M that is far better than activity against WI-38 (normal cell line) (IC50, 393.7 mu M). The drug (RFC) minimizes the cellular proliferation and has significant wound healing capacity of the infected tissue with MCF-7 cells. The probe shows significant nuclear fragmentation with increase in the expression of apoptotic markers. Growth inhibition analysis in 3D tumor spheroid model showed the inhibition of breast cancer MCF-7 cells.