Fluorescence sensor for water in organic solvents prepared from covalent immobilization of 4-morpholinyl-1, 8-naphthalimide

Abstract

A new fluorescent dye, N-allyl-4-morpholinyl-1,8-naphthalimide (AMN), was synthesized as a fluorescence indicator in the fabrication of a sensor for determining water content in organic solvents. To prevent leakage of the fluorophore, AMN was photo-copolymerized with acrylamide, (2-hydroxyethyl)methacrylate, and triethylene glycol dimethacrylate on a glass surface treated with a silanizing agent. The sensing mechanism is based on the solvatochromic feature of the covalently immobilized AMN. The fluorescence intensity of AMN decreased with increasing water contents when it was excited at 400 nm. In the range of ca. 0.00-4.40% (v/v), the fluorescence intensity of AMN changed as a linear function of water content. The sensor exhibited satisfactory reproducibility, reversibility, and a response time (t (99)) of the order of 50 s. The detection limit was solvent-dependent, when acetonitrile was used as the solvent, and the detection limit could be as low as 0.006% (v/v) of water. Additionally, the prepared sensor is pH-insensitive and possesses a relatively long lifetime of at least one month.

Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

“…Highest quantum yield observed for NB_II (Φ f = 0.60). The presence of electron donating substituents may also increase the separation between the singlet (S 1 ) and its closer triplet excited state, thus decreasing the intersystem crossing (ISC) and favoring the fluorescence deactivation channel [24][25][26][27][28][29][30][31][32] (Figs. 5 and 6).…”

A Highly Selective Fluorescent Sensor for Cu2+ Based on a Covalently Immobilized Naphthalimide Derivative

“…21 The optode membrane was prepared according to the following procedure. 21,36 A mixture of 2.9 mL of 2-hydroxyethyl methacrylate (HEMA), 10 mg of compound 1, 45 mg of benzoin ethyl ether, 0.12 g benzophenone, and 0.2 mL of triethanolamine was first prepared. Drops of the solution were applied to a dust-free poly(tetrafluoroethylene) (PTFE) plate.…”

“…33 However, only a few fiber-optic fluorescence sensors based on naphthalimide derivatives have been developed. [34][35][36] To the best of our knowledge, no report has been published about a fluorescent copper sensor based on naphthalimide derivatives conjugated to the active surface of glass slides. In this article, we developed a copper(II)-selective fluorescent sensor based on covalently immobilized derivative 1 of naphthalimide on the active surface of glass slides.…”

Colorimetric Signaling of Water Content in Acetonitrile by Phenolic Dye-Fluoride Complexes

“…Selective and sensitive optical signaling systems that utilize multifunctional dye molecules, 3 such as merocyanines, 4 flavones, 5 chalcone, 6 3-hydroxychromone, 7 naphthalimide, 8 and indole derivatives 9 have been developed as probes to sense the water content of commonly used organic solvents.…”