Development of amide-based molecular cages for the highly selective and sensitive detection of nicotine

Nicotine is a harmful sympathomimetic drug associated with serious health issues. Herein, a novel amide-based bistren-type cage, BiP-Am, has been developed for the selective fluorescence-based sensing of nicotine in human urine samples and cigarettes. The corresponding detection limit features a value of 0.4 nM, among the best reported in the literature. Selectivity experiments demonstrate that BiP-Am can efficiently detect nicotine in the presence of multiple interfering analytes such as sodium, potassium, urea and uric acid. A plausible mechanism has been proposed herein, revealing that nicotine is showing an inner-filter effect quenching the BiP-Am fluorescence emission. Our strategy poses a facile and versatile method for nicotine detection in portable applications.