Selective fluorometric sensing of Hg2+ in aqueous solution by the inhibition of PET from dithia-15-crown-5 ether receptor conjugated to 4-amino-1,8-naphthalimide fluorophore

Ratiometric Detection of Mercury (II) Ions in Living Cells Using Fluorescent Probe Based on Bis(styryl) Dye and Azadithia-15-Crown-5 Ether Receptor

“…All experiments were carried out at pH 6.0 (acetate buffer, 0.01 M), which, on the one hand, is rather close to slightly acidic environment inside A549 cells [ 31 ] (these cells were used in cellular experiments below), and on the other hand, excludes protonation at the azacrown ether nitrogen atom and related spectral shifts. Protonation at nitrogen atom of N -phenylazadithia-15-crown-5 ether receptor in water solution occurs at pH values lower than 4.0, as it has been shown for the previously synthesized 4-amino- N -aryl-1,8-naphthalimide [ 32 , 33 ], where the N -phenylazadithia-15-crown-5 ether receptor is present as an N -aryl group and not conjugated with the chromophoric part of the molecule. In this sense, probe 1 should be even less basic due to delocalization of the amine nitrogen lone pair electrons into the π-system of positively charged styryl(pyridinium) fragment.…”

“…The dependence of R on intracellular concentration of Hg 2+ in the 0–60 nM range demonstrated a good linearity with a correlation coefficient of 0.99 ( Figure S35 ). From the slope of this linear dependence ( r ) and standard deviation of the ratio R ( ), the lower detection limit for Hg 2+ in cells ( ) was found to be 37 nM, according to the Equation (5) [ 47 ], which is comparable with the other fluorescent Hg 2+ chemosensors [ 33 , 48 ]. …”

Demonstration of Selective Single-Barium Ion Detection with Dry Diazacrown Ether Naphthalimide Turn-on Chemosensors

“…Ba(ClO4)2 addition led to a concentration dependent increase in fluorescence centered near 530 nm in probes 1B, 1D, and 1E, when excited at λmax obtained from UV-Vis spectrum, suggesting turn-on fluorescence by changes to photoinduced electron transfer (PET). 17 Similarly, fluorescence analysis as a function of absorption wavelength from 430-460 nm showed no significant change in the emission intensity profile (SI Fig. S4).…”

“…14 As such, 1,8-naphthalimide fluorophores appended with crown ethers have been used as colorimetric and fluorescent sensors for the detection of ions and small molecules that are of great significance in environment, health, and energy. [15][16][17][18] Several 1,8-naphthalimide chemosensors have been developed for detection of cations, anions, and small polar molecules. [19][20][21][22] However, 1,8-naphthalimide based chemosensors with selective response to Ba 2+ remain underdeveloped.…”

Low cost, high sensitivity detection of waterborne Al3+ cations and F− anions via the fluorescence response of a morin derivative dye

“…NaMSA can still be immobilised in a permeable membrane [6], but preparation of such membranes is difficult and time-consuming. Plasticised PVC membranes often show slow responses [16] and may suffer from dye leaching [17]. In this work , we take advantage of the good solubility of NaMSA in water to extend the use of NaMSA as an Al 3+ -selective 'off → on' fluorescent sensitiser [9,18] when immobilised in a phase transfer membrane to a morin derivative, instead using the NaMSA dissolved in water, avoiding the need for membrane preparation.…”