A new “turn-on” molecular switch for idiosyncratic detection of Al3+ ion along with its application in live cell imaging

Abstract

A highly sensitive, reversible, reusable and fluorogenic “turn-on” probe (HBTC) is fabricated for the sole detection of Al³⁺. On incremental addition of Al³⁺ in a solution of HBTC in ACN : H₂O (4 : 1), a sharp “turn-on” emission enhancement is observed at 480 nm. The reversibility of the probe (HBTC) was displayed on the addition of F⁻ solution. The detection limit is found to be of the order of 10⁻⁹ M which suggests that HBTC can detect Al³⁺ at a very minute level. The mechanism for Al³⁺ detection in ACN : H₂O (4 : 1) is attributed to forbidding CN isomerization and ESIPT process simultaneously turning on the chelation-enhanced fluorescence process. The reusability and real-time application of the probe are also studied. Bioimaging study reveals that HBTC can detect Al³⁺ in human breast cancer cells (MDA-MB-231). Electronic structure of the probe is explained by density functional theory.