Related Experiment Video
Updated: Aug 2, 2025

Detection of Bacteria Using Fluorogenic DNAzymes
Published on: May 28, 2012
Diphenyl imidazole-based fluorescent chemosensor for Al3+ and its Al3+ complex toward water detection in food
Yucun Liu1, Ning Li1, Yongling Zhang2
1College of Chemistry, Jilin Normal University, Siping 136000, China.
Abstract:
A sophisticated fluorescent chemosensor, 2-(4-nitrophenyl)-4,5-diphenyl-1H-imidazole (NPDI), was designed and synthesized through a one-step condensation reaction. NPDI exhibited a fluorescence enhancement response toward Al3+, accompanied by significant emission color change without interference from other tested metal ions. The binding stoichiometry and mechanism was corroborated using various techniques. The limit of detection (LOD) for Al3+ could reach 7.25 × 10-8 mol/L and the binding constant was found to be 1.47 × 105 L/mol. Furthermore, the in-situ formed NPDI·Al complex functioned a secondary chemosensor for water by quenching effect. The fluorescence quenching mechanism could be attributed to hydrogen bonding interaction of nitro substituent with water. The LOD was calculated to be 0.012 %, indicating NPDI·Al heightened sensitivity to water. Additionally, NPDI·Al complex was employed for the moisture detection in the surroundings. Finally, the practical application of NPDI·Al complex had been successfully used in the determination of water content in food products.
Related Concept Videos
Photoluminescence: Applications
Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
High-Performance Liquid Chromatography: Types of Detectors

