A Highly Selective Colorimetric and Ratiometric Two-Photon Fluorescent Probe for Fluoride Ion Detection

Abstract

A naphthalimide-based highly selective colorimetric and ratiometric fluorescent probe for the fluoride ion displayed both one- and two-photon ratiometric changes. Upon reaction with the F(-) (TBA(+) and Na(+) salts) anion in CH(3)CN as well as in aqueous buffer solution, probe 1 shows dramatic color changes from colorless to jade-green and remarkable ratiometric fluorescence enhancements signals. These properties are mechanistically ascribed to a fluoride-triggered Si-O bond cleavage that resulted in a green fluorescent 4-amino-1,8-naphthalimide.

The 8-Silyloxyquinoline Scaffold as a Versatile Platform for the Sensitive Detection of Aqueous Fluoride

“…Lastly, we chose to include a sulfonamide at position 5 in sensor 2 as this functionality has been shown to dramatically increase the fluorescence of 8-hydroxyquinoline derivatives. 30 We synthesized 2 according to Scheme 1 and investigated its response to fluoride by addition of 1 mM TBAF to a dioxane solution of 2. Gratifyingly, we observed a marked change in both the absorbance and fluorescence emission spectra of the solutions upon addition of TBAF, producing a desilylated fluorescent product 3 (Supporting Information, Figure S1) with ε = 6600 M −1 cm −1 and Φ = 0.16 ( Figure 1).…”

“…Recently, colorimetric and fluorescent detection of fluoride using small organic molecules has drawn growing attention because of the simplicity, accuracy and low cost of the assay format. [20][21][22][23][24][25][26][27][28][29][30] However, the sensors have to overcome the hydration enthalpy barrier of fluoride in water (-121 kcal/mol) so that it can be used in real world aqueous sample. As a consequence, although numerous sensor platforms have been reported in the literature, the fluoride detection limit of these sensors is generally in the mid micromolar range for aqueous samples.…”

Autoinductive Exponential Signal Amplification: A Diagnostic Probe for Direct Detection of Fluoride

“…[18] A large number of sensors for fluoride anion have been developed to date. [19,20] The United States Environmental Protection Agency (EPA) enforceable standard for drinking water is no more than 4 mg L À1 (higher levels may result in osteoflurosis), and ideal levels should be no more than 2 mg L À1 to protect against dental fluorosis. Therefore, relevant sensors for fluorides should be able to produce a detectable diagnostic signal this concentration range.…”

A 4‐Amino‐1,8‐Naphthalimide Derivative for Selective Fluorescent Detection of Palladium(II) Ions

“…During the detection process, PdCl 2 solution was added to the solution of 1 in PBS, and the mixture was incubated at 37 8C for 24 h to ensure sufficient completion of the reaction. Upon excitation at 433 nm, an emission peak centered at 536 nm gradually appeared as 4 was formed [16][17][18][19] through the Pd(II)-induced intramolecular rearrangement of 1 A C H T U N G T R E N N U N G (Scheme 1).…”