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Research Article
Senthilnithy R
Open University of Sri Lanka
Corresponding Author
ORCiD: https://orcid.org/0000-0001-9557-8750
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This work is licensed under a CC BY 4.0 License. Read Full License
Bathophenanthroline (BPhen) is a versatile bidentate ligand for transition metals, also frequently used as a universal colorimetric probe for Fe(II). The effect of pH on the fluorescence intensity of BPhen and quenching constant of Fe(II) were studied at different pH values using working solutions of 50% ethanol buffered with acetate buffer. Fluorescence intensity of a 3.0 μM Bphen solution in 50% ethanol buffered at pH 6.6 with acetate buffer was selectively quenched by Fe(II) at 25 °C. The LOD of 19 nM at 3.3 σ and the linear range of 63 nM – 224 nM with R2 = 0.9919 revealed that this method is more sensitive than the colorimetric method (detection range =1.8 μM - 18 μM). Quenching of the BPhen-Fe(II) complex is temperature-dependent, which may be due to the increased stability of the formed complex with temperature, supporting a static quenching mechanism. Interference from foreign ions on the fluorescence of the BPhen-iron(II) complex was also studied. A tolerance limit exceeding 5% was observed and recorded. The interference from cations, Ni(II), Co(II), and Cu(II), was relatively higher, while the most common anions showed only a little to no interference. In response time analysis, the fluorescence intensity, which remains constant after 10 minutes, reveals that the system approached equilibrium. This method would be quicker and more accurate than a colorimetric method due to the absence of a solvent extraction step.
Keywords
Bathophenanthroline, turn-off sensor, fluorescence quenching, Stern-Volmer plot
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A new preprint design is coming!
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This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Research Article
Senthilnithy R
Open University of Sri Lanka
Corresponding Author
ORCiD: https://orcid.org/0000-0001-9557-8750
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 08 Jun, 2021
No community comments so far
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Bathophenanthroline (BPhen) is a versatile bidentate ligand for transition metals, also frequently used as a universal colorimetric probe for Fe(II). The effect of pH on the fluorescence intensity of BPhen and quenching constant of Fe(II) were studied at different pH values using working solutions of 50% ethanol buffered with acetate buffer. Fluorescence intensity of a 3.0 μM Bphen solution in 50% ethanol buffered at pH 6.6 with acetate buffer was selectively quenched by Fe(II) at 25 °C. The LOD of 19 nM at 3.3 σ and the linear range of 63 nM – 224 nM with R2 = 0.9919 revealed that this method is more sensitive than the colorimetric method (detection range =1.8 μM - 18 μM). Quenching of the BPhen-Fe(II) complex is temperature-dependent, which may be due to the increased stability of the formed complex with temperature, supporting a static quenching mechanism. Interference from foreign ions on the fluorescence of the BPhen-iron(II) complex was also studied. A tolerance limit exceeding 5% was observed and recorded. The interference from cations, Ni(II), Co(II), and Cu(II), was relatively higher, while the most common anions showed only a little to no interference. In response time analysis, the fluorescence intensity, which remains constant after 10 minutes, reveals that the system approached equilibrium. This method would be quicker and more accurate than a colorimetric method due to the absence of a solvent extraction step.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
This is a list of supplementary files associated with this preprint. Click to download.
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