Flavones Fluorescence-Based Dual Response Chemosensor for Metal Ions in Aqueous Media and Fluorescence Recovery

• Published in: Journal of fluorescence Vol. 30; no. 4; pp. 759 - 772
• Main Authors: Fatma, Nisha, Mehata, Mohan Singh, Pandey, Nupur, Pant, Sanjay
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-07-2020; Springer Nature B.V
• Subjects: Analytical Chemistry; Aqueous solutions; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedicine; Biophysics; Biotechnology; Chemical sensors; Chemoreceptors; Colorimetry; Copper; Ferrous ions; Fluorescent indicators; Materials recovery; Metal ions; Original Article; Photoexcitation; Rapid quenching (metallurgy); Selectivity; Hydroxyflavone; Chemosensor; Dual response; Metal ions; Colorimetric
• ISSN: 1053-0509; 1573-4994
• DOI: 10.1007/s10895-020-02540-z

Responsiveness of sensing materials 3-hydroxyflavone (3HF) towards metal ions in aqueous medium has been explored following photoexcitation. 3HF exhibited both colorimetric and fluorescence (FL) turn–off response towards Cu
2+
and Fe
2+
with high sensitivity and selectivity. Meanwhile, the distinct colour change and the rapid quenching of FL intensity provide naked-eye detection. On successive addition of Cu
2+
and Fe
2+
ions, FL of 3HF was “turned off,” whereas there is no change in wavelength of FL bands. Quenching efficiencies for Cu
2+
and Fe
2+
ions are 88% and 49%, respectively. The detection limit of the sensor towards Cu
2+
and Fe
2+
was 1.54 μM and 1.98 μM, respectively. The binding strategy between 3HF and metal ions (Cu
2+
, Fe
2+
) and the nature of quenching have been explored with the Benesi-Hildebrand and Stern-Volmer plots, respectively. The FL of 3HF significantly quenched in the presence of Cu
2+
ions, and then recovered upon addition of HCl, providing the possibility of constructing a sensitive Cu
2+
-HCl off-on fluorescent probe. Moreover, the proposed simple, quick response and visual test strip-based chemosensor could be used for the detection of Fe
2+
and Cu
2+
ions.