Fluorescence-based Probe for Heavy Metal Detection in Water

Abstract

Fluorescence is the emission of light by means of a substance that has absorbed light or different electromagnetic radiation. In most cases, the emitted light has a longer wavelength, and consequently decrease energy, than the absorbed radiation. Several fluorescent chemicals can be used as fluorescent probes to detect heavy metals which include fluorescein (FAM) and porphyrins. Fluorescein is a natural compound and dye while porphyrins are a member of heterocyclic macrocycle organic compounds, composed of 4 modified pyrrole subunits interconnected at their α carbon atoms with the aid of methine bridges (=CH−). The objective of this study is to detect the presence of heavy metals ions in water using selected fluorescent chemical probes and to study the sensitivity and selectivity of the selected fluorescent chemical probes towards different concentrations of heavy metals. In general, the study was done by mixing heavy metal solution with the chemical probes to see the changes in fluorescent intensity of the chemical probes in different heavy metal concentration. From the fluorescence analysis result by comparing Ni (II) and Pb (II), it shows that fluorescein was more selective and sensitive towards Ni (II) while porphyrins was more selective and sensitive towards Pb (II). In conclusion, detection of heavy metals using fluorescent chemical probes (FAM and porphyrin) shows promising results with Fluorescein was found to be more selective and sensitive towards Ni (II) while porphyrin was more selective and sensitive towards Pb (II).