A sensing approach based on rhodamine associated Bis-1,2,3-triazole probe for targeted recognition of Fe3+ ions: Imaging on DL-tumor cells and molecular modelling

Abstract

The discriminatory identification of Fe3+ ions among the series of metal ions in an aqueous medium is a significant importance of chemosensors, a bis-1,2,3-triazole associated with rhodamine (R1) was developed with a perfect hetero-atomic cavity. The chemosensor R1 was synthesized using a simple and well-known click reaction to generate a nitrogen enrich triazoles unit in the R1. Through the naked eyes, Fe3+ ion was detected on the spot at tremendously low concentrations with the alterations of fluorescent from non-fluorescent and colored from colorless R1. After formation of complex R1:Fe3+, it is highly pH sustained range from pH 2.0–10.0 and reversible with cysteine in solution and on a paper strip. The formed complex R1:Fe3+, it exhibits excellent pH stability within the range of pH 2.0–10.0. Moreover, its reversibility can be achieved through interaction with cysteine, both in solution and on a paper strip. R1 was also feasible to detect Fe3+ ions in real water samples. In DL-tumor cells, cytocompatibility was investigated using MTT assay, and found that cell viability was greater than 80 %. The binding interaction of R1 with the crystal structure of the anti-apoptotic protein Bcl-XL (PDB ID: 2YXJ) showed that R1 fits well at the active site of Bcl-XL with binding energy (ΔG) − 10.42 kcal/mol (Ki = 22.97 nM). The result shows that R1 is cytocompatible and may be exploited as a fluorescent probe for selectively detecting Fe3+ in living cells.