ESIPT+TICT‐Based Near‐IR Detection of Al³⁺ and F⁻ in Live Cells: Molecular Docking with Acetylcholinesterase

Abstract The interplay of ESIPT+TICT mechanisms in 1,8‐naphthalimide–hydroxyquinoline ( NQ−OH ) molecular rotor were reported for the near‐IR ‘turn‐on’ emission (λ max 600 nm) and ratiometric (A 405nm /A 345nm ) absorbance‐based detection of Al 3+ ions in aqueous medium and live cells which were supported by NMR, IR and CV techniques. The limit of detection (LOD) for Al 3+ ions is 100 nM and 14.57 nM. The self‐assembled spherical aggregates of NQ−OH transformed into cuboidal aggregates upon coordination with Al 3+ ions supported by microscopic and dynamic light scattering (DLS) techniques. The complex NQ‐OH +Al 3+ was further used for the secondary detection of F − ions in aqueous medium via displacement approach with LOD as low as 2.67 nM. A deeper study revealed that the NQ−OH is a solvatochromic dye. Probably, the NQ−OH either in the aggregated state or in the coordination state with Al 3+ ions, showed an increase in the emission intensity at 600 nm due to inhibition of the ESIPT process and trigger of the TICT process. We have demonstrated the utility of NQ−OH for the detection of Al 3+ ions and NQ‐OH +Al 3+ complex for the detection of F − ions in MCF7 live cells. We have also discussed the molecular docking studies of NQ−OH with acetylcholinesterase enzyme.