Rational design, green synthesis of reaction-based dual-channel chemosensors for cyanide anion

A highly selective fluorescent and chromogenic probe for CN- detection and its applications in bioimaging

In this study, 3-ethyl-2-methylbenzothiazolium iodide and nitrophenyl-2-furancarboxaldehyde were used to synthesize a new fluorescent and chromogenic dual channel signal cyanide ion probe M, which showed high selectivity towards CN^- analysis and strong antijamming capability towards other anions. When CN^- is present in the solution, probe M indicates an obvious blue shift in UV-vis absorbance spectra, which can be observed clearly by unaided eyes. The limits of detection (LODs) of CN^- based on fluorescence and UV-vis absorbance were 0.11 μM and 0.16 μM, respectively. The mechanism of fluorescent and chromogenic cyanide ion detection refers to the nucleophilic addition of cyanide ion to carbon atom of -C˭N- in the benzothiazole. The π-conjugation and ICT transition between furfural and benzothiazole were broken due to this non-reversible reaction, resulting in the color change and fluorescent characterizations. In addition, probe M also showed the excellent optical properties and high biocompatibility, which enables the practical application of CN^- tracing in biomedical systems.

Amphiphilic carbon dots for sensitive detection, intracellular imaging of Al3

In this paper, a simple and effective method was designed to synthesize hydrophobic carbon dots. Subsequently, amphiphilic fluorescent carbon dots (A-CDs) were synthesized by further surface modification. The result A-CDs show excellent optical properties with a quantum yield of 16.9%. It was interestingly found that morin (MR) and its fluorescent metal-ion complex (MR-Al³⁺) can successfully coordinate on the surface of A-CDs, the emission of A-CDs completely overlapped the absorption peak of MR-Al³⁺. Thus, the prepared A-CDs can be used as an effective fluorescent probe for Al³⁺ based on a fluorescence resonance energy transfer process. The sensing platform can realize real-time detection of Al³⁺ within 0.5 min. The fluorescence signals of the system were linearly correlated with the concentration of Al³⁺ over a range of 8-20 μM, with a detection limit of 0.113 μM. The method was also successfully applied to image the distribution of Al³⁺ in Human Umbilical Vein Endothelial Cells.

Rational design, synthesis of reaction-based dual-channel cyanide sensor in aqueous solution

A new dual-channel sensor for the detection of cyanide was developed based on the conjugated of naphthalene and malononitrile. Upon the addition of CN(-), the sensor displayed very large blue-shift in both fluorescence (80nm) and absorption (120nm) spectra. The sensor of cyanide was performed via the nucleophilic attack of cyanide anion to vinylic groups of the sensor with a 1:1 binding stoichiometry and the color changed of the sensor is mainly due to the intramolecular charge transfer process improvement. The intramolecular charge transfer progress was blocked with color changed and fluorescence blue-shift. The mechanism of sensor reaction with CN(-) ion was studied using (1)H NMR and mass spectrometry.

Structure–reactivity correlation in selective colorimetric detection of cyanide in solid, organic and aqueous phases using quinone based chemodosimeters

The five new colorimetric chemodosimeters sense cyanide selectively and sensitively in aqueous and organic media via a nucleophilic addition mechanism exhibiting quantitative structure–reactivity correlation.

A simple chemosensor for the dual-channel detection of cyanide in water with high selectivity and sensitivity

By a deprotonated mechanism, the simple chemosensorHYshowed high sensitivity and selectivity for cyanide in aqueous media.

Fluorescent "turn-on" detecting CN(-) by nucleophilic addition induced Schiff-base hydrolysis

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.

A colorimetric and fluorescent cyanide chemosensor based on dicyanovinyl derivatives: utilization of the mechanism of intramolecular charge transfer blocking

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.

Colorimetric probes designed to provide high sensitivity and single selectivity for CN− in aqueous solution

Easily-made probe L1 recognized CN⁻ by the deprotonation process and the detecting limit is 5 × 10⁻⁶ mol L⁻¹.

Rationally designed anion-responsive-organogels: sensing F⁻ via reversible color changes in gel-gel states with specific selectivity

Through the rational introduction of the multi self-assembly driving forces and F(-) sensing sites into a gelator molecule, low-molecular-weight organogelators L1 and L2 were designed and synthesized. L1 and L2 showed excellent gelation ability in DMF and DMSO. They could form stable organogels (OGL1 and OGL2) in DMF and DMSO with very low critical gelation concentrations. OGL1 and OGL2 could act as anion-responsive organogels (AROGs). Unlike most of the reported AROGs showing gel-sol phase transition according to the anions' stimulation, OGL1 could colorimetrically sense F(-) under gel-gel states. Upon addition of F(-), OGL1 showed dramatic color changes, while the color could be recovered by adding H(+). Moreover, OGL1 showed specific selectivity for F(-), other common anions and cations could not lead to any similar response. What deserves to be mentioned is that the report on specific sensing of anions under gel-gel states is very scarce. The gel-gel state recognition can endow the organogel OGL1 with the merits of facile and efficient properties for rapid detection of F(-). Therefore, OGL1 could act as a F(-) responsive smart material.