A new phenothiazine-based selective visual and fluorescent sensor for cyanide

Abstract

A new donor-π-acceptor derived from phenothiazine, namely 2-(2-((10-hexyl-10H-phenothiazin-3-yl)methylene)-3-oxo-2,3-dihydroinden-1-ylidene) malononitrile (PTZON) was synthesized and fully characterized, and its potential as a fluorescent sensor for cyanide anion was investigated. The PTZON showed a visible absorption band at 564 nm corresponds to an intramolecular charge transfer (ICT) and an emission band at 589 nm in CH 3 CN/H 2 O. The results of cyanide anion titration revealed ratiometric changes in both absorption and fluorescence spectra as a result of the nucleophilic addition of cyanide anion via Michael addition. The optical studies, FT-IR spectra, NMR, high-resolution mass, and DFT calculations confirmed the sensing mechanism. The selectivity of PTZON as a cyanide anion fluorescent sensor was proved in mixed solvent solutions, and the sensitivity was as low as 0.011 µM, which is far lower than the value allowed by the United States Environmental Protection Agency for drinking water (1.9 µM). Also, the detection limit of PTZON was assessed to be 3.39 μM by the spectrophotometric method. The binding stoichiometry between PTZON and cyanide anion was found to be 1:1 as evidenced by mass spectra. TLC silica-coated plates test strips demonstrated the fluorescent detection of cyanide anion.

A novel approach for the synthesis of nanostructured Ag3PO4 from phosphate rock: high catalytic and antibacterial activities

“…They can be employed not only as fertilizers but also, they have been exploited effectively as catalysts in a wide range of organic transformation [ 19 – 21 ]. In continuation of our ongoing program to develop an interesting catalyst at low-cost [ 22 – 27 ], we describe in this paper, a novel chemical wet method-based dissolution–precipitation reactions using Moroccan natural phosphate (NP) as phosphorus precursor to synthesize of the nanostructured Ag 3 PO 4 as catalyst for the reduction of 4-NP to 4-AP in the presence of sodium borohydride using aqueous phase and its antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. To the best of our knowledge, no studies have been performed on the development of Ag 3 PO 4 from natural phosphate and testing its catalytic activity for the reduction reaction in aqueous solution, and its antibacterial activity.…”

Review of Research into the Determination of Acrylamide in Foods

“…Fluorescence sensors express signals generated by molecular recognition in the form of fluorescence (changes in fluorescence intensity and wavelength) to achieve information transmission [112,113]. Due to the merits of high sensitivity, good selectivity, and convenient use, fluorescence sensing analysis has been widely used and has made great progress in recent years [114][115][116]. Quantum dots (QDs) have unique photophysical properties such as high fluorescence quantum yield, size-controlled fluorescence, and photobleaching resistance, and have been widely used in the field of fluorescence sensing [117,118].…”

Rapid and Highly Selective BODIPY Based Turn‐Off Colorimetric Cyanide Sensor**

“…Furthermore, we also screened the fluorescence sensing studies of BODIPY-BAL with the same concentrations CN À ions. According to the fluorescence titration of BODIPY-BAL upon increasing the concentration of CN À ion, the fluorescence intensity of the BODIPY-BAL increased and new peaks were aroused at 507 nm and 560 nm caused by the π!π* and n!π* electronic transition of the cyanide functionality [31] (Figure 3a). Quantum yield of the BODIPY-BAL was also calculated in different solvents (see the SI) and so the fluorescence quantum yields of the dye are low in all solvents as unexpectedly.…”