Highly selective fluorescence sensors for biogenic amines and copper (II) ion

Abstract

This research aims to design and synthesize the molecular sensors for biogenic amine sensing and fabricate 3D microfluidic device. In the case of biogenic amine, it can be classified into two group, the first group is catecholamine and the second group is histamine and histidine. For catecholamine sensing, coumarin aldehyde (CA) and pyrene boronic acid (PBA) formed intermolecular assembly in the presence of neurotransmitters and induced FRET on process from PBA to CA. The result showed DA and NE performed a guest linker including intermolecular assembly of CA and PBA resulting in FRET on/off process. In the case of histidine and histamine sensing, we designed histamine sensor, consisting of histamine blue (HB) loaded in nanoporous silica modified surface by fluorescein isothiocyanate (FC). The result showed that histamine induced an increasing fluorescent intensity at 525 nm (ex. 340 nm) by energy transfer process from HB to FC. No fluorescence response was observed in the case of histidine due to the electronic repulsion between negative charge on carboxylate based fluorescein dye on the surface and carboxylate group in histidine. In the case of 3D microfluidic device, we developed the quantitative assay by fabrication of FBA and fluorescein dye on the paper. This research designed the device into two part of assay zone and control zone for normalization the factor of flow-through rate of the sample. This device provided the linear range from 10-100 micro molar of copper ions concentration and it was applied to measure Cu2+ ion in blood sample with an acceptable value of 103.38% recovery.