Microwave‐Assisted Synthesis of Imidazoquinazoline for Chemosensing of Pb2+ and Fe3+ and Living Cell Application

An efficient dual‐responsive fluorescent probe based on imidazoquinazoline has been synthesised using microwave‐assisted solvent‐free condition. Its sensing behaviour towards Pb2+ and Fe3+ has been investigated separately through fluorescence, absorbance and visual fluorescence colour changes in different solvent systems. Interestingly, the binding event triggers selective “turn‐on” response to Pb2+ and ratiometric response to Fe3+ against other commonly coexistent metal ions. The observed experimental data has been rationalized in terms of theoretical calculations. The living cell imaging experiment demonstrated the practical value of the sensor in mapping intracellular Fe3+ and Pb2+ distributions in biological systems. A simple, efficient and practical methodology for the synthesis of imidazoquinazoline using microwave‐assisted reaction strategy is developed. The molecular system acts as bifunctional sensor for the detection of Pb2+ and Fe3+ with different fluorescence response in different solvent condition. More interestingly, probe displays ratiometric response to Fe3+ in aqueous acetonitrile solution. The probe features excellent selectivity, high sensitivity, good reversibility and low detection limit.