A simple coumarin based "fluorescent On" probe for the selective detection of Al3+ along with its application in live cell imaging via AGS cell line.

• Herein, we report the synthesis and cation sensing properties of a new fluorescence reversible "turn-on" probe (HCBP). • HCBP selectively detects Al3+ in aqueous methanol medium at physiological pH with the enhancement of emission intensity. • Limit of detection (LOD) of the probe towards Al3+ is found to be in the order of 10-9 M. • Electronic structure and sensing mechanism of the probe is interpreted by DFT calculations. • The fluorescence imaging is performed using gastric cancer cells (AGS). A new coumarin based fluorescent switch (HCBP) has been fabricated which displays high selective sensing towards Al3+ among other metal cations at physiological pH. On gradual addition of Al3+ specifically, HCBP shows a brilliant "turn-on" emission enhancement of about ∼13-fold with about 50 nm red shift at 481 nm in MeOH/H 2 O (1/1, v/v) solution. The fluorescent switch is proven to be a reversible probe by addition of EDTA gradually into the HCBP-Al3+ solution. Detection limit as well as Binding constant values have been calculated and found to be in the order of 10−9 M and 103 M-1 respectively. DFT and TDDFT studies are conducted with the probe to establish a similarity between theoretical and experimental outcomes. We can also use this new fluorescent switch as a biomarker kit as it has shown a brilliant potential in the application of live cell imaging using gastric cancer cell (AGS cell). [ABSTRACT FROM AUTHOR]