Selective Detection Of Cyanide Research Articles

A new cascade reaction-based colorimetric and fluorescence “turn on” dual-function probe for cyanide and hydrazine detection

Selective detection of cyanide (CN−) and hydrazine (N2H4) are highly desirable owing to the highly toxic properties of these species. We report herein a new cascade reaction-based colorimetric and fluorescence “turn on” dual-function probe (HBTM-HC) for CN− and N2H4 detection with long wavelength emission (620 nm) and a large Stokes shift (122 nm). In DMSO/H2O (3/7, v/v, PBS 10 mM, pH = 9.1) solution, HBTM-HC displays highly selective and sensitive detection of CN− and N2H4 with the assistance of masking agents (acetone was used to mask N2H4, and Fe2+ was used to mask CN−). The detection limits of HBTM-HC for CN− and N2H4 were calculated to be 1.38 × 10−6 M and 5.47 × 10−6 M, respectively. The sensing mechanisms for CN− and N2H4 were proved to undergo cascade reactions, which results in deprotection of levulinate group and releasing of compound HBTM. In addition, probe HBTM-HC has been successfully applied to fluorescence imaging of N2H4 in live MCF-7 cells, detect CN− in sprouting potatoes and apple seeds, and detect CN− and N2H4 in real water samples with high recovery rates (92.0%–104.5%) and small relative standard deviations (≤7.15%).

Smartphone coupled with a paper-based optode: Towards a selective cyanide detection

A low-cost on-paper sensor based on 5,10,15-tritolylcorrolatocobalt(III) triphenylphosphine, CoTTCorr(PPh3), was developed for cyanide detection in aqueous solutions. The sensor was coupled to a smartphone and used a home-written color intensity analysis software in order to record and interpret the colorimetric response. The detection of cyanide was possible down to 0.053 mg/L, an order of magnitude lower than the value of 0.5 mg/L set by the World Health Organization (WHO) for safe short-term exposure of cyanide in potable water. The colorimetric sensor had selectivity toward cyanide ions over the anions Cl-, Br, F-, NO2, SCN-, OA[Formula: see text]-,ClO4-, H2PO4- and HCO3- while the influence of NO3- ions on the sensor optical response towards cyanide was overcome by optimization of the ionophore/anion-exchanger ratio inside the sensing material. The best performance was obtained for the optode with an ionophore to exchanger ratio of 1:3. The optimized optodes were employed for quantification of cyanide content added to potable water and saliva.

Reversible Addition of Cyanide to Triphenylamine Attached Difluoroboron β‐Diketonate Facilitated Selective Colorimetric and Fluorimetric Detection of Cyanide Ion

Nucleophilic addition of cyanide on a new triphenylamine attached difluoroboron β‐diketonate {4‐[4‐(diphenylamino) phenyl]‐2,2‐difluoro‐6‐methyl‐2H‐1,3,2‐dioxaborinin‐1‐ium‐2‐uide (C4)} breaks the conjugation readily and thereby offers efficient and selective detection of cyanide. A rational mechanism based on UV/Vis, fluorescence, NMR (1H, 11B, and 19F) and HRMS analysis and DFT calculations has been proposed. The detection limit was found to be 0.36 µM. A test strip assay using the title compound has also been applied to detect CN– in aqueous solution for real‐time applications.

A Novel Material Fluorescence Probe Based on Covalently Functionalized Graphene Oxide by Aminocoumarin for Detection of CN−

Owing to the hazardness, the sensitive and selective detection of cyanide (CN−) in water or water-containing systems has still been a puzzle plaguing scientists all around the world. In this paper, a novel fluorescence probe based on covalently functionalized graphene oxide (GO) by aminocoumarin for highly selective detection of CN− in deionized water was prepared under the action of EDC/NHS. This probe bears aminocoumarin group as the recognition site and fluorophore, and its fluorescence quantum yield is increased by 0.07. Simultaneously, by loading on GO, the dispersibility, selectivity and reversibility were soundly improved, which facilitated the detection process. The fluorescence spectra showed that the probe has high selectivity and sensitivity for cyanide, and has potential application in real water.

Rapid and Selective Detection of Cyanide Anion by Enhanced Fluorescent Emission and Colorimetric Color Changes at Micromole Levels in Aqueous Medium

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.

Far‐Red‐Emitting TEG‐Substituted Squaraine Dye: Synthesis, Optical Properties, and Selective Detection of Cyanide in Aqueous Solution

A comprehensive study of the photophysical properties of triethylene glycol monomethyl ether (TEG)‐substituted squaraine dye SQ1 is presented. SQ1 exhibits strong absorption and intense fluorescence emission in the far‐red spectral region and high photostability. Interestingly, bis‐tegylated SQ1 was characterized to exhibit properties different from its tetrahydroxy analog (SQ2), to which we ascribe attenuation of intermolecular interactions as a result of steric hindrance through introduction of two TEG chains adjacent to the squaraine core. The photophysical properties of SQ1 were also investigated as a function of temperature and pH. In cetyltrimethylammonium bromide (CTAB) micellar media (1.0 mm), the fluorescence quantum yield of SQ1 increased dramatically to 0.22, compared with 0.02 in water. Based on this discovery, SQ1 was found to display excellent sensitivity and selectivity to the presence of cyanide ions (CN–), with a limit of detection of 1.7 µm. The hypothesized CN– sensing mechanism was probed, and visual test strips were developed. This work broadens the family of squaraine dyes and demonstrates SQ1 for use as a fluorescent or visual sensing probe.

표면음향파 화학센서를 이용한 수용액 중 시안화이온의 선택적인 고감도 검출

표면음향파 화학센서를 이용한 수용액 중 시안화이온의 선택적인 고감도 검출

Selective and Sensitive Detection of Cyanide Based on the Displacement Strategy Using a Water-Soluble Fluorescent Probe.

A water-soluble fluorescent probe (C-GGH) was used for the highly sensitive and selective detection of cyanide (CN−) in aqueous media based on the displacement strategy. Due to the presence of the recognition unit GGH (Gly-Gly-His), the probe C-GGH can coordinate with Cu2+ and consequently display ON-OFF type fluorescence response. Furthermore, the in situ formed nonfluorescent C-GGH-Cu2+ complex can act as an effective OFF-ON type fluorescent probe for sensing CN− anion. Due to the strong binding affinity of CN− to Cu2+, CN− can extract Cu2+ from C-GGH-Cu2+ complex, leading to the release of C-GGH and the recovery of fluorescent emission of the system. The probe C-GGH-Cu2+ allowed detection of CN− in aqueous solution with a LOD (limit of detection) of 0.017 μmol/L which is much lower than the maximum contaminant level (1.9 μmol/L) for CN− in drinking water set by the WHO (World Health Organization). The probe also displayed excellent specificity for CN− towards other anions, including F−, Cl−, Br−, I−, SCN−, PO4 3−, N3 −, NO3 −, AcO−, SO4 2−, and CO3 2−.

A highly sensitive and selective cyanide detection using a gold nanoparticle-based dual fluorescence–colorimetric sensor with a wide concentration range

In this study, a simple analytical system is presented for the detection of cyanide with a wide concentration range, which is respectively based on the fluorescent and colorimetric properties of gold nanoparticles. This dual-functional system can work directly for aqueous medium and expand efficiently a wide detection range over three orders of magnitudes for cyanide determination. By using the fluorescence method, the lowest concentration for quantification of cyanide ions is 1.0×10−7M, and the sensitivity is good enough for the determination of cyanide in drinking water. To recognize higher concentration of cyanide for industrial sewage monitoring, the colorimetric behavior can be used as an alternating tool for field tests from naked eye. The system also provides an excellent selectivity toward cyanide over other common interfering anions and metal ions, thus enabling the ability to monitor cyanide contamination in environmental samples. Furthermore, several real water samples spiked with cyanide, including local tap water, drinking water, lake water, and sea water, were analyzed, and the experimental results demonstrated that this sensing system exhibited excellent recoveries for these practical water samples. Our attempt may provide a cost-effective, rapid and simple solution for the recognition and determination of different levels of cyanide contamination in aqueous samples.

In Situ Formation of Phosphorescent Molecular Gold(I) Cluster in a Macroporous Polymer Film to Achieve Colorimetric Cyanide Sensing

A highly phosphorescent molecular Au(I) cluster capable of rapid, sensitive, and selective detection of cyanide has been successfully fabricated. The origin of the outstanding sensing performance of the molecular Au(I) cluster toward cyanide is justified by X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) analyses. The response mechanism employed with the molecular Au(I) cluster and the cost-effectiveness in cyanide detection affords several key sensor features, making this molecular Au(I) cluster-based sensor unique compared to other cyanide sensing schemes. Importantly, by exploring the phosphorescent properties of the molecular Au(I) cluster in solid state, we demonstrate the first example of the molecular gold(I) cluster-based macroporous sensing film for colorimetric detection of cyanide in complex samples, including red wine, coffee, juice, and soil. Remarkably, the as-prepared sensing film inherits the sensing ability of the molecular Au(I) cluster, and offers a high mechanical flexibility and novel opportunities for real-time monitoring cyanide release in cassava manufacturing.

Selective detection of cyanide by a polyfluorene-based organoboron fluorescent chemodosimeter

Organoboron-based polymeric fluorescent probes have been designed and synthesized for the sensitive and selective detection of toxic cyanide ions by a fluorescence “turn off” mechanism. Bis-(bromohexyl)-polyfluorenes have been synthesized by Pd catalyzed Suzuki cross-coupling polymerization. Its treatment with (Mes)2BF achieved organoboron-appended polyfluorene (PFBP). PFBP that is soluble in common organic solvents shows bright blue luminescence under UV-irradiation. The substantial quenching of the luminescence of a PFBP solution in the presence of toxic cyanide ions (CN−) has been observed. This is due to the formation of strong covalent bonds between the cyanide ions and trivalent boron centres of the side chains of the PFBP, which is further supported by NMR studies. The polyfluorene backbone of the PFBP acts as the fluorophore, and the boron centre as the cyanide acceptor. This novel type of polymeric material will find a potential application in sensor technology, as the detection limit is very low at ∼0.5 μM.

Water soluble and fluorescent copolymers as highly sensitive and selective fluorescent chemosensors for the detection of cyanide anions in biological media

We report a simple colorimetric method based on a water soluble polymer (WSP) for the sensitive and selective detection of cyanide in a biological solution. The WSPs were prepared from a radical polymerization of a methacrylate with a cyanide chemosensor moiety based on a coumarin–dicyano-vinyl derivative motif, and the polymer was then rendered water soluble by copolymerizing this hydrophobic monomer with other glyco-conjugated methacrylate derivatives. The lowest concentration for the quantification of cyanide ions was 0.05 μM, and the polymer exhibited nearly no calorimetric response to the presence of other common anions. Therefore, the chemical incorporation of some carbohydrates, as lactose or its usual monosaccharide moieties (glucose, lactose), represents a new method for the implementation of polymers for the detection of cyanide anions in water, exhibiting both good selectivity and efficiency.

A simple, sensitive and selective detection of cyanide in organic as well as aqueous media by fluorene-based chromogenic host

A receptor bearing fluorene as spacer, urea as a binding site and nitrophenyl as signalling unit was designed and synthesised. Designed receptor has displayed good selectivity and sensitivity for cyanide over other anions such as F− , Cl− , Br− , I− , , , CH3COO− , , SCN− , , , OCN− , , and PhO− by visual as well as spectroscopic methods. Naked-eye detection of cyanide in natural environment extends its practical applicability in real-time monitoring.

Coumarin-Cu(II) Ensemble-Based Cyanide Sensing Chemodosimeter

An "ensemble"-based chemodosimeter 1-Cu(II) for cyanide detection is reported. 1-Cu(II) can recognize a cyanide ion over other anionic species to show a marked fluorescence enhancement under aqueous conditions. "Off-on" fluorescence change of 1-Cu(II) is proceeded by addition of cyanide, which induces decomplexation of the Cu(II) ion from nonfluorescent 1 followed by hydrolytic cleavage of the resulted Schiff base to give a strongly fluorescent coumarinaldehyde (2). The selective detection of cyanide with 1-Cu(II) for biological application was also performed in HepG2 cells.

A Label‐Free Gold‐Nanoparticle‐Based SERS Assay for Direct Cyanide Detection at the Parts‐per‐Trillion Level

Cyanide is an extremely toxic lethal poison known to humankind. Developing rapid, highly sensitive, and selective detection of cyanide from water samples is extremely essential for human life safety. Driven by the need, here we report a gold-nanoparticle-based label-free surface-enhanced Raman spectroscopy (SERS) system for highly toxic cyanide ion recognition in parts-per-trillion level and to examine gold-nanoparticle-cyanide interaction. We have shown that the SERS assay can be used to probe the gold nanoparticle dissociation process in the presence of cyanide ions. Our experimental data indicates that gold-nanoparticle-based SERS can detect cyanide from a water sample at the 110 ppt level with excellent discrimination against other common anions and cations. The results also show that the SERS probe can be used to detect cyanide from environmental samples.

Highly sensitive and selective cyanide detection via Cu2+ complex ligand exchange

A new type of fluorescent probe (1) with two triazole groups that are conjugated with a carbazole moiety was synthesized by a Cu(I)-catalyzed alkyne-azide click reaction for the selective and sensitive detection of cyanide via fluorescence enhancement by ligand exchange and metal ion removal.

Gold‐Nanocluster‐Based Fluorescent Sensors for Highly Sensitive and Selective Detection of Cyanide in Water

AbstractA novel, gold‐nanocluster‐based fluorescent sensor for cyanide in aqueous solution, which is based on the cyanide etching‐induced fluorescence quenching of gold nanoclusters, is reported. In addition to offering high selectivity due to the unique Elsner reaction between cyanide and the gold atoms of gold nanoclusters, this facile, environmentally friendly and cost‐effective method provides high sensitivity. With this sensor, the lowest concentration to quantify cyanide ions could be down to 200 × 10−9 M, which is approximately 14 times lower than the maximum level (2.7 × 10−6 M) of cyanide in drinking water permitted by the World Health Organization (WHO). Furthermore, several real water samples spiked with cyanide, including local groundwater, tap water, pond water, and lake water, are analyzed using the sensing system, and experimental results show that this fluorescent sensor exhibits excellent recoveries (over 93%). This gold‐nanocluster‐based fluorescent sensor could find applications in highly sensitive and selective detection of cyanide in food, soil, water, and biological samples.

Cyanine dye-based chromofluorescent probe for highly sensitive and selective detection of cyanide in water

Cyanine dye Cy5 was used to be a probe for highly selective detection of trace cyanide in water by using a convenient two-phase strategy. The detection limit of both the fluorescent and colorimetric assay for cyanide is below 1.9 μM, the maximal allowance level for drinking water set by the World Health Organization.

Visible and near-infrared chemosensor for colorimetric and ratiometric detection of cyanide

A chemosensor system has been developed for rapid and selective detection of cyanide. The sensory molecules have the donor–acceptor type of structure and are designed by tuning the LUMO level or their reactivity towards cyanide. This sensory system is able to selectively distinguish cyanide among fluoride and many other anions at micromolar concentrations and instantly detect cyanide at ambient temperatures with a detection limit down to 1.0 µM. Multiple sensory signals are available and can be used for both qualitative monitoring and quantitative determination of cyanide, including high-contrast visual color change, fluorescence quenching and enhancement in the visible and near-infrared spectral regions.

Turn-on fluorescent cyanide sensor based on copper ion-modified CdTe quantum dots

A new fluorescent sensor for the sensitive and selective detection of cyanide (CN(-)) in aqueous media was developed herein. The sensing approach is based on CN(-)-modulated quenching behavior of Cu(2+) toward the photoluminescence (PL) of CdTe quantum dots (QDs). In the presence of CN(-), the PL of QDs that have been quenched by Cu(2+) was found to be efficiently recovered, which then allows the detection of CN(-) in a very simple approach. Experimental results showed that the pH of the buffer solution, concentration of copper ions, and size of CdTe QDs all influenced the response of the sensor to CN(-). Under the optimal conditions, a good linear relationship between the PL intensity and the concentration of CN(-) can be obtained in the range of 3.0 x 10(-7) to 1.2 x 10(-5) M, with a detection limit as low as 1.5 x 10(-7) M. In addition, the present fluorescent sensor possesses remarkable selectivity for cyanide over other anions, and negligible influences were observed on the cyanide detection by the coexistence of other anions or biological species (such as albumin and typical blood constituents). Therefore, we expect the proposed copper ion-modified QDs to be an efficient and reliable sensing system to monitor cyanide concentration in environmental or clinical applications.