Anbu, Sellamuthu, Paul, Anup, Surendranath, Kalpana, Sidali, Ahmed and Pombeiro, Armando J.L. 2021. Naphthalimide-phenanthroimidazole incorporated new fluorescent sensor for “turn-on” Cu2+ detection in living cancer cells. Journal of Inorganic Biochemistry. 220 111466. https://doi.org/10.1016/j.jinorgbio.2021.111466
| Title | Naphthalimide-phenanthroimidazole incorporated new fluorescent sensor for “turn-on” Cu2+ detection in living cancer cells |
|---|---|
| Type | Journal article |
| Authors | Anbu, Sellamuthu, Paul, Anup, Surendranath, Kalpana, Sidali, Ahmed and Pombeiro, Armando J.L. |
| Abstract | In recent years, fluorescent sensors have emerged as attractive imaging probes due to their distinct responses toward bio-relevant metal ions. However, the bioimaging application main barrier is the ‘turn-off’ response toward paramagnetic metal ions such as Cu2+ under physiological conditions. Herein, we report a new sensor (2-methyl(4-bromo-N-ethylpiperazinyl-1,8-naphthalimido)-4-(1H-phenanthro[9,10-d]imidazole-2-yl) phenol) NPP with multifunctional (Naphthalimide, Piperazine, Phenanthroimidazole) units for fluorescent and colourimetric detection of Cu2+ in an aqueous medium. Both absorption and fluorescence spectral titration strategies were used to monitor the Cu2+-sensing property of NPP. The NPP displays a weak emission at ca. 455 nm, which remarkably enhances (⁓3.2-fold) upon selective binding of Cu2+ over a range of metal ions, including other paramagnetic metal ions (Mn2+, Fe3+, Co2+). The stoichiometry, binding constant (Ka) and the LOD (limit of detection) of NPP toward Cu2+ ions were found to be 1:1, 5.0 (± 0.2) × 104 M−1 and 6.5 (± 0.4) × 10−7 M, respectively. We have also used NPP as a fluorescent probe to detect Cu2+ in live (human cervical HeLa) cancer cells. The emission intensity of NPP was almost recovered in HeLa cells by incubating ‘in situ’ the derived Cu2+ complex (NPP-Cu 2+ ) in the presence of a benchmark chelating agent such as EDTA (ethylenediaminetetraacetate). The fluorescent emission of NPP was reverted significantly in each cycle upon sequencial addition of Cu2+ and EDTA to the NPP solution. Overall, NPP is a novel, simple, economic and portable sensor that can detect Cu2+ in biological and environmental scenarios. |
| Article number | 111466 |
| Journal | Journal of Inorganic Biochemistry |
| Journal citation | 220 |
| ISSN | 0162-0134 |
| Year | 2021 |
| Publisher | Elsevier |
| Accepted author manuscript | License CC BY-NC-ND 4.0 File Access Level Open (open metadata and files) |
| Digital Object Identifier (DOI) | https://doi.org/10.1016/j.jinorgbio.2021.111466 |
| Publication dates | |
| Published online | 24 Apr 2021 |
| Published in print | Jul 2021 |
| Funder | Fundação para a Ciência e Tecnologia |
| FCT | |
| RSC | |
| FCT and IST | |
| Engineering Laboratory | |
| University of Westminster |