Quantum dots and fluorescence compounds for biogenic amine sensing

Abstract

The simple approach for biogenic amine sensing electron transfer (ET) process and ligand exchange mechanism has been constructed by using fluorophore-micellar probe. In this work, coumarin derivative (CouS1) and carbon nanoparticles namely branch-polyethyleneimine modified carbon dots (N-CDs) were synthesized and used as fluorophore for constructing the probe. In the presence of SDS, the fluorescence intensity of these fluorophores was enhanced leading to a high sensitivity in sensing application. Upon the addition of various metal ions into the both solutions of CouS1 and N-CDs in the presence of SDS, Co2+ ion exhibited the highest fluorescence quenching in the both solution due to ET process. As a result, the CouS1/SDS/Co2+ and N-CDs/SDS/Co2+ probe were constructed for discrimination of biogenic amine. In the case of CouS1/SDS/Co2+ probe, the fluorescence recovery of CouS1/SDS was observed upon the addition of histidine because of removal of Co2+ ion from the probe by histidine. On the contrary, a high fluorescence quenching of CouS1/SDS/Co2+ was observed due to co-bonding of histamine with Co2+ ion. Moreover, CouS1/SDS/Co2+ enables to give a benefit discrimination of imidazole based biogenic amine by naked-eye approach. In the case of N-CDs/SDS/Co2+ probe, the fluorescence recovery of N-CDs/SDS was observed in particular of presented histidine. The detection limits of CouS1/SDS/Co2+ and N-CDs/SDS/Co2+ over histidine were 45 µM and 74 µM, respectively. This suggests that these probes can be applied for analytical detection of histidenemia both normal and histidenemia patients. Additionally, molecular logic gate was developed form these different sensing spectrum upon the different stimuli of Co2+ ion, histidine and histamine.