Determination of urotropine using cucurbit[7]uril-palmatine complex as a highly sensitive fluorescent probe

Abstract

A new method for sensitive and selective determination of urotropine has been developed using the cucurbit[7]uril-palmatine complex as a fluorescent probe. The complex exhibits high fluorescence in aqueous solution, which is quenched in the presence of urotropine. The fluorescence quenching value, <img src='/image/spc_char/delta.gif' border=0><em>F</em>, is directly proportional to the concentration of urotropine in the range of 0.004–1.26 μg mL⁻¹, with detection limit as sensitive as 0.0013 μg mL⁻¹. The proposed method has been successfully applied to determine urotropine in food samples with good precision and accuracy. The stoichiometry and binding affinity as well as the nature of the binding behavior are determined using spectrofluorimetry, ¹H NMR and molecular modeling theoretical calculations.