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A new chemosensor Sz based on Schiff-base group as recognition site and naphthalene as the fluorescence signal group was designed and synthesised. It could fluorescent "turn-on" detect cyanide (CN(-)) via a novel mechanism of nucleophilic addition induced Schiff-base hydrolysis. Adding the CN(-) into the solution of Sz could induce Sz to emit blue fluorescence at 435 nm instantly. Moreover, Sz could also colorimetric detect CN(-). Upon the addition of CN(-), the Sz showed dramatic color change from yellow to colorless. These sensing procedures could not be interfered by other coexistent competitive anions such as F(-), AcO(-), H2PO4(-) and SCN(-). In addition, Sz showed high sensitivity for CN(-), the detection limits is 3.42×10(-8) M of CN(-), which is far lower than the WHO guideline of CN(-) in drinking water (less than 1.9×10(-6) M). The CN(-) test strips based on Sz could act as a convenient CN(-) test kits., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Chemosensor (CS1) was designed and synthesized by simple green chemistry procedure. CS1 exhibited both colorimetric and fluorescence turn-off responses for cyanide (CN(-)) ion in aqueous solution. The probe showed an immediate visible color changes from yellow to colorless and green fluorescence disappearance when CN(-) was added. The mechanism of chemosensor reaction with CN(-) was studied using (1)HH NMR and (13)C NMR spectroscopies and mass spectrometry. Moreover, test strips based on the sensor were fabricated, which served as convenient and efficient CN(-) test kits., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A highly selective chemosensor 1 based on an acylhydrazone group as binding site and naphthalene group as the fluorescence signal group were described, which could instantly detect CN(-) in water with specific selectivity and high sensitivity. The detection of cyanide was performed via the nucleophilic attack of cyanide anion on the carbonyl group, which could be confirmed by (1)H NMR, (13)C NMR, ESI-MS and DFT calculations. The addition of CN(-) to sensor 1 induced a remarkable color change from colorless to yellow and generated a blue fluorescence, these sense procedure could not interfered by other coexistent competitive anions (F(-), Cl(-), Br(-), I(-), AcO(-), H2PO4(-), HSO4(-), ClO4(-), SCN(-), S(2-), NO3(-) and SO4(2-)). The detection limits were 5.0×10(-7) M and 2.0×10(-9) M of CN(-) using the visual fluorescent color changes and fluorescence spectra changes respectively, which is far lower than the WHO guideline of 1.9×10(-6) M. Test strips based on sensor 1 were fabricated, which could act as a convenient and efficient CN(-) test kit to detect CN(-) in pure water for "in-the-field" measurement., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Comprehensive Summary: The cyanide anion (CN–) is known to be one of the most toxic anions. Therefore, there is an urgent need to develop a reliable, sensitive, selective, rapid and effective method for the detection of CN–. Here, a self‐assembly strategy based on pillar[5]arene P5 and azine derivative AZ was used to construct supramolecular sensors, and it was found that the detection effect of CN– was significantly improved by the assembly strategy. The sensitivity of the assembled sensor P5‐AZ to CN– is more than 10 times higher than that of AZ. The detect mechanism was further investigated by theoretical calculations and 1H NMR. The results showed that AZ detects CN– by a deprotonation process with fluorescence enhancement, while P5‐AZ improves the sensitivity of CN– recognition through hydrogen bonding, anion‐π and anion‐dipole interactions, as well as the strong bonding ability of the assembly. Supramolecular assembly P5‐AZ has the advantages of low toxicity, high sensitivity, and more importantly, it provides a method to detect CN– sensitivity in the aqueous phase and organisms by host‐guest assembly. [ABSTRACT FROM AUTHOR]

In this study, we prepared an efficient chemosensor based on 2,3-diaminophenazine hydrochloride, and it exhibited good dissolvability in water; more importantly, it could act as an efficient chemodosimeter for the selective detection of CN− in pure water. Upon reacting with CN−, 2,3-diaminophenazine hydrochloride (Q1) displayed a remarkable visible and fluorescence response simultaneously with significant changes in both absorption and fluorescence spectra. Furthermore, the absorption and fluorescence detection limits of CN− were 1.95 × 10−7 M and 1.13 × 10−9 M, respectively. For practical applications, test strips based on this chemosensor could serve as convenient CN− detection tools. The chemosensor was also successfully applied to the detection of CN− in plant seeds and several natural water samples. [ABSTRACT FROM AUTHOR]

One main source of cyanide (CN−) exposure for mammals is through the plant consumption; thus, the sensitive and selective cyanide detection in plant tissue is a significant and urgent work. Here, a simple sensor N′‐(2,4‐dihydroxybenzylidene)naphtha[2,1‐b]furan‐2‐carbohydrazide (Q1‐3) was designed and synthesized for selective and sensitive dual‐channel detection of cyanide in aqueous medium (DMSO/H2O, 1:9, v/v). Acylhydrazone and phenolic hydroxyl groups on Q1‐3 are the recognition sites, and naphthofuran group is the signal report group. The intramolecular charge transfer between the benzene group and naphthofuran group was impeded because of the electron‐withdrawing groups (hydroxyl) on sensor Q1‐3. Interestingly, the sensor Q1‐3 exhibited an intramolecular charge transfer absorption band at 400 nm and emission band at 500 nm, respectively, directly realizing an “OFF–ON” response after the deprotonation process induced by cyanide anions in aqueous medium (DMSO/H2O, 1:9, v/v). Notably, this sensor was successfully applied to detect cyanide anions in food samples, which proves a very simple and selective platform for on‐site monitoring of cyanide in agriculture samples. In addition, the test strips and silica gel plates based on Q1‐3 were also fabricated, which could act as test kits and silica gel plates for convenient and efficient detection of cyanide anions. [ABSTRACT FROM AUTHOR]

A novel sensor (AHP5) comprising a thioacetohydrazone-bridged bispillar[5]arene was developed and shown to fluorescently sense cyanide ions. The sensor manifested a response specific to cyanide over other common anions (SCN−, AcO−, HSO4−, H2PO4−, I−, Br−, ClO4−, Cl−, and F−) in DMSO/H2O (9 : 1, v/v) solution. Upon treatment with cyanide, AHP5 exhibited a significant fluorescence response accompanied by marked changes in its fluorescence spectra. Furthermore, competitive anions had no obvious influence on the probing behavior. Notably, investigation of the recognition mechanism indicated that AHP5 recognized CN− through a deprotonation procedure accompanied by the breaking of intermolecular hydrogen bonds. Furthermore, the sensor was successfully applied to the detection of cyanide in cyanide-containing water samples. [ABSTRACT FROM AUTHOR]

A water-soluble fluorescent chemosensor (D) based on 1, 8-naphthalimide derivative has been designed and synthesised as a new fluorescent sensor for successive detection of Fe3+and CN−. Fluorescence measurements show that chemosensorDhas excellent fluorescent-specific selectivity and high sensitivity for Fe3+over many other metal ions in pure water. Moreover, the complex ofDand Fe3+(D–Fe3+) displayed high sensitivity for CN−over many other anions in the same medium. Even more important, the recognition of the sensorDfor Fe3+andD–Fe3+complex for CN-could be used successfully in pure water. The test strips based onDandD–Fe3+exhibited good selectivity to Fe3+and CN,-respectively, we believe the test strips could serve as convenient and efficient Fe3+and CN−test kits. [ABSTRACT FROM AUTHOR]

As a novel macrocyclic host, pillar[5]arene can selectively recognise guest molecules in organic solvents. In this study, a fluorescent chemosensor composed of a functionalised-pillar[5]arene and Cu2+metal complex (PN–Cu), which shows good selectivity for CN−anions, has been designed and synthesised. Complexation between PN–Cu and anions has been probed by means of various fluorescence-based methods. PN–Cu, as a turn-on fluorescence chemosensor showed high selectivity towards CN−ions in comparison to other anions, and its detection limit for CN−was calculated as 9.03 × 10−7 M. The PN–Cu sensor can serve as a recyclable component in sensing materials. Moreover, the interaction between the singly functionalised pillar[5]arene and Cu2+has been probed through various tests. Based on the remarkable selectivity of the chemosensor PN–Cu, we propose that it might be used as a potential material for CN−recognition. Scheme 2. The proposed sensing mechanism of PN for copper(II) and cyanide in DMSO. [ABSTRACT FROM PUBLISHER]

Taking advantages of both the well-known phenazine structure and the mechanism of the supramolecular self-assembly and deprotonation process, the fluorescent and colorimetric sensor ( ZL ) was designed and synthesized, behaving as a circulation utilization (above 10 times) receptor for selective detection of cyanide anion (CN − ) in aqueous media. Upon the addition of CN − , the sensor displayed obvious color changes from yellow to jacinth by naked eyes and the fluorescence immediately quenched (< 10 s). With respect to other common anions, the sensor possessed high selectivity and sensitivity (0.05 μM) for cyanide anions. In addition, the test strips of ZL were fabricated, which could serve as practical colorimetric and fluorescent sensor for “in-the-field” measurements. [ABSTRACT FROM AUTHOR]

Taking advantage of the special nucleophilicity of cyanide, a new simple colorimetric chemosensor has been synthesised. This allows a deprotonation reaction to monitoring the cyanide. With the addition of CN−to the chemosensor aqueous solution, which could induce a change in the solution colour from yellowish to deep yellow, while no colour change could be observed in the presence of other hackneyed anions, by which CN−can be distinguished from other anions immediate with the naked eye. At the same time, a fluorescence quenching was implemented upon adding cyanide into the chemosensor aqueous solution. The absorption spectra detection limits of the chemosensor for cyanide was 5.35 × 10−8 M and the fluorescence spectra detection limit was 2.63 × 10−8 M. The cyanide test strips based on the chemosensor could serve as a convenient cyanide test kits. Furthermore, the chemosensor was successfully applied to detect cyanide in sprouting potatoes. A novel chemosensorFCis demonstrated to sense CN−in aqueous media based on the mechanism of deprotonation reactions and electric charge transferring. This work provides a novel approach for the selective recognition of CN−anions. [ABSTRACT FROM PUBLISHER]

A colorimetric and fluorescent cyanide probe bearing naphthol and sulfahydrazone groups has been designed and synthesized. This structurally simple probe displays a rapid response and high selectivity for cyanide in DMSO/EtOH (v/v = 2:8) solution. The addition of CN−to the sensorp-toluenesulfonyl-2-hydroxy-1-naphthylhydrazone (L3) induced a remarkable color change from pale-yellow to yellow, and green fluorescence changed to yellow. The1H NMR titration and DFT calculations suggested that the selective sensing process is based on a nucleophilic addition reaction of cyanide to imine. Test strips based on sensorL3were fabricated, which could act as a convenient and efficient test kit to detect CN−for “in-the-field” measurements. [ABSTRACT FROM AUTHOR]

A colorimetric and fluorescent cyanide chemosensor L1 bearing a coumarin group has been designed and synthesized. It showed immediate visible color changes from yellow to colorless and blue fluorescence enhancement when CN− was added. The mechanism of the CN− anion recognition process was examined using 1H NMR titration, FT-IR spectroscopy, ESI-MS and DFT calculations. The sensor was highly sensitive with a detection limit of 7.72 × 10−8 M of CN−. Test strips based on the sensor L1 were fabricated, which could act as a convenient and efficient CN− test kit to detect CN− for “in-the-field” measurements. [ABSTRACT FROM AUTHOR]

In this work, a novel Schiff-Base ( Q1 ) which based on 5-(4-nitrophenyl)-2-furan and naphtho[2,1 -b ]furan-2-carbohydrazide was designed to act efficiently in a chemodosimeter approach for the selective detection of cyanide in aqueous medium. The recognition progress occurred via deprotonating between the hydrazide moiety of Q1 and cyanide. When exposed Q1 to the low concentration solution of cyanide anion, there was a significant color change from yellow to orange in visible light and accompanied with a strong and broad red shift (from λ max-ab = 400 nm to λ max-ab = 468 nm) in the UV–vis absorption spectrum. Meanwhile, a dramatically decrease almost 4 times of the emission maximum of Q1 took place from 775 (a.u.) to 204 (a.u.), and the color of the solution changed from bright orange to dim red, which can be saw by naked-eyes under the UV lamp (365 nm). However, without any signal changes after the addition of other common anions, especially the basic anions such as F − , AcO − , H 2 PO 4 − and SCN − . Notably, this probe can serve as a recyclable component in sensing materials. The corresponding experiment proved that this probe can be repeated use above 10 times. (Scheme 1) On the basis of these observations and supporting mechanistic analyses, it is concluded that the recyclable probe Q1 must be a promising cyanide anion indicator that is attractive in terms of its selectivity, ease-of-use, rapid response (<3 s), and the low, naked-eye discernible cyanide detection limit it, also it will be regarded as an environmental friendly material which can sensing cyanide anion in aqueous medium and making great contribution to the development of cyanide anion sensors. [ABSTRACT FROM AUTHOR]

A turn-on fluorescent chemosensor ( H - 1 ) for cyanide anions based on dihydroxy phenazine was designed and synthesised. The sensor H - 1 exhibits high sensitivity and good selectivity for cyanide in pure water. The CN − response mechanism involves a hydrogen bonding and deprotonation process in the sensor, which induced prominent fluorescence enhancement. The detection limit of the sensor toward CN − is 5.65 × 10 −7 M, and other anions had nearly no influence on the probing behavior. In addition, test strips based on the sensor were fabricated, which also exhibit a good selectivity to CN − in water. Notably, this sensor was successfully applied to detect CN − in food samples, which proves a very simple and selective platform for on-site monitoring of CN − in agriculture samples. [ABSTRACT FROM AUTHOR]

A reversible and water-soluble 2,4-dimethyl-7-amino-1,8-naphthyridine (ZR) was synthesized to fluorescently sense CN− in water. Interestingly, the deprotonation reaction between cyanide and the primary amine would block the intramolecular charge transfer of the electron donor and acceptor, thus, affecting the ICT efficiency and optical properties of the sensing system. [ABSTRACT FROM AUTHOR]

A highly selective chemosensor 1 based on an acylhydrazone group as binding site and naphthalene group as the fluorescence signal group were described, which could instantly detect CN− in water with specific selectivity and high sensitivity. The detection of cyanide was performed via the attack of cyanide anion on the carbonyl group, which could be confirmed by 1H NMR, 13C NMR, ESI-MS and DFT calculations. The addition of CN− to sensor 1 induced a remarkable color change from colorless to yellow and generated a blue fluorescence, these sense procedure could not interfered by other coexistent competitive anions (F−, Cl−, Br−, I−, AcO−, H2PO4−, HSO4−, ClO4−, SCN−, S2−, NO3− and SO42−). The detection limits were 5.0×10−7 M and 2.0×10−9 M of CN− using the visual fluorescent color changes and fluorescence spectra changes respectively, which is far lower than the WHO guideline of 1.9×10−6 M. Test strips based on sensor 1 were fabricated, which could act as a convenient and efficient CN− test kit to detect CN− in pure water for 'in-the-field' measurement. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The cyanide anion (CN–) is known to be one of the most toxic anions. Therefore, there is an urgent need to develop a reliable, sensitive, selective, rapid and effective method for the detection of CN–. Here, a self‐assembly strategy based on pillar[5]arene P5 and azine derivative AZ was used to construct supramolecular sensors, and it was found that the detection effect of CN– was significantly improved by the assembly strategy. The sensitivity of the assembled sensor P5‐AZ to CN– is more than 10 times higher than that of AZ. The detect mechanism was further investigated by theoretical calculations and 1H NMR. The results showed that AZ detects CN– by a deprotonation process with fluorescence enhancement, while P5‐AZ improves the sensitivity of CN– recognition through hydrogen bonding, anion‐π and anion‐dipole interactions, as well as the strong bonding ability of the assembly. Supramolecular assembly P5‐AZ has the advantages of low toxicity, high sensitivity, and more importantly, it provides a method to detect CN– sensitivity in the aqueous phase and organisms by host‐guest assembly. [ABSTRACT FROM AUTHOR]

Abstract: A simple CN− sensor bearing a naphthol and an imine group was designed and synthesized, which showed both a colorimetric and a fluorescence turn-on response for cyanide ions in aqueous solution. The probe shows an immediate visible change in color from yellow to orange which then becomes colorless followed by a final change to pink, when cyanide is added; these color changes can be readily observed visually. The mechanism of the reaction of the probe with the cyanide ion was established by using 1H NMR and FT-IR spectroscopy and mass spectrometry. Moreover, test strips based on the sensor were fabricated, which could act as a convenient and efficient CN− test kit. [Copyright &y& Elsevier]

A fluorescent and colorimetric sensor based on naphtho[2,1 -b ]furan-2-carbohydrazide and 2-hydroxy-1-naphthaldehyde ( Q1-1 ) was developed via straightforward reaction from inexpensive reagents. It exhibited rapid response, superb selectivity, and swift sensitivity toward CN based on its promising photo-induced electron transfer (PET) feature. Q1-1 not only can sense CN through sharp colorimetric and selective turn-on fluorescence dual-channel responses in EtOH/H 2 O (7:3, v/v) HEPES solution, but also have strong anti-interference toward other common anions, especially the basic anions such as F − , AcO − , H 2 PO 4 − and SCN − . Notably, this sensor was successfully applied to detect CN − in food samples, which proves a very simple and selective platform for on-site monitoring of CN − in agriculture samples. In addition, the test strips based on Q1-1 were fabricated, which could act as convenient and efficient CN − test kits. [ABSTRACT FROM AUTHOR]

A chemosensor (CS) was designed and synthesized by simple method. Dual-channel instant detection of CN − was achieved under acidic conditions. It showed an immediate visible color change from yellow to colorless and blue fluorescence appearance when CN − was added. Colorimetric and fluorometric methods showed the detection limits of CN − were 3.9×10 −8 and 3.1×10 −9 M, respectively. The mechanism of chemosensor reactions with CN − ion was examined using 1 H NMR spectroscopy, FTIR spectroscopy, and DFT calculations. Test strips, which served as convenient and efficient CN − test kits, were fabricated based on the sensor. [ABSTRACT FROM AUTHOR]

Abstract: Chemosensors CF1–CF3 were designed and synthesized via a simple green chemistry procedure. CF3 could instantly detect cyanide anion in aqueous solution by dual-channel model. The detection limit of CF3 for CN- is 10nM. Test strips based on CF3 could act as a convenient and efficient CN− test kit. [Copyright &y& Elsevier]

In this work, we constructed a supramolecular gel (PN-G) by phenazine derivative, which can ultrasensitive detect cyanide (detection limit equals to 4.18 × 10−10 M). The decrease of fluorescent intensity displayed a linear relationship in the range of 0–0.4 equivalents of cyanide. And no significant fluorescence quenching was observed for all used interfering ions. The cyanide recognition mechanism of PN-G was verified by XRD, NMR, MS and SEM. With addition of cyanide to the supramolecular gel (PN-G), cyanide broken π-π stacking of PN-G , and then PN-G undergoes a nucleophilic addition reaction with CN−, resulting in fluorescence quenched. A supramolecular gel (PN-G) was constructed, which could ultrasensitively detect cyanide. Image 1 • Constructed a supramolecular gel by self-assembly. • A novel supramolecular gel for highly selective and sensitive detection of cyanide. • Taking advantage of a simple mechanism of nucleophilic addition reaction. [ABSTRACT FROM AUTHOR]