Dual-channel Chemosensor Research Articles

Dual channel chemosensor for successive detection of environmentally toxic Pd2+ and CN− ions and its application to cancer cell imaging

BackgroundDetecting and neutralizing Pd2+ ions are a significant challenge due to their cytotoxicity, even at low concentrations. To address this issue, various chemosensors have been designed for advanced detection systems, offering simplicity and the potential to differentiate signals from different analytes. Nonetheless, these chemosensors often suffer from limited emission response and complex synthesis procedures. As a result, the tracking and quantification of residual palladium in biological systems and environments remain challenging tasks, with only a few chemosensing probes available for commercial use. ResultsIn this paper, a straightforward approach for the selective detection of Pd2+ ions is proposed, which involves the design, synthesis, and utilization of a propargylated naphthalene-derived probe (E)-N'-((2-(prop-2-yn-1-yloxy)naphthalen-1-yl)methylene)benzohydrazide (NHP). The NHP probe exhibits sensitive dual-channel colorimetry and fluorescence Pd2+ detection over other tested metal ions. The detection process is performed through a catalytic depropargylation reaction, followed by an excited state intramolecular proton transfer (ESIPT) process, the detection limit is as low as 11.58 × 10−7 M under mild conditions. Interestingly, the resultant chemodosimeter adduct (E)-N'-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide (NHH) was employed for the consecutive detection of CN− ions, exhibiting an impressive detection limit of 31.79 × 10−8 M. Validation of both detection processes was achieved through 1H nuclear magnetic resonance and density functional theory calculations. For real-time applications of the NHP and NHH probes, smartphone-assisted detection, and intracellular detection of Pd2+ and CN− ions within HeLa cells were studied. SignificanceThis research presents a novel naphthalene derivative for visually detecting environmentally toxic Pd2+ and CN− ions. The synthesized probe selectively binds to Pd2+, forming a chemodosimeter. It successfully detects CN− ions through colorimetry and fluorimetry, offering a low detection limit and quick response. Notably, it's the first naphthalene-based small molecule to serve as a dual probe for toxic analytes - palladium and cyanide. Moreover, it effectively detects Pd2+ and CN− intracellularly in cancer cells.

Coumarin-derived Schiff base as a colorimetric and fluorescent dual-channel chemosensor for detecting HSO4− and bioimaging & biosensing in Zebrafish

A naked-eye colorimetric and fluorescent response dual-channel Schiff base chemosensor (L1) with simple structure and excellent performance was synthesized by the ammoniacal aldehyde condensation reaction of 6-amino coumarin with 4‑methoxy salicylaldehyde. The chemical sensor L1 showed high sensitivity and selectivity to HSO4− that caused obvious colorimetric (from yellow to colorless) and fluorescent (from no fluorescence to orange fluorescence) response in mixed solvents (EtOH/H2O, v/v = 9:1). And the binding constants (Ka) and limit of detection (LOD) for HSO4− were 6.4 × 103 M−1 and 4.63 × 10−7 M, respectively. The 1H NMR and HR-MS studies confirmed that the sensing mechanism for L1 was attributed to CN hydrolysis cleavage promoted by HSO4−. L1-loaded test strips could be employed for detecting HSO4− under daylight and 365 nm UV light without resorting to any expensive instrumentation. In addition, it was also applied to the detection of trace HSO4− in simulated water samples, including drinking water, and tap water. It was worth mentioning that L1 has been successfully used to recognition of HSO4− in the Zebrafish organism, indicating that the practical application of sensor L1 in the field of biology and environment provided the possibility.

A Novel Colorimetric and Fluorometric Dual-Channel Chemosensor based on A Conjugated Perylene-Benzothiazole System for Highly Selective Detection of Cyanide in Aqueous Media.

A novel cyanine compound based on the conjugated perylene-benzothiazole system (PBI) as a colorimetric and fluorometric dual-channel sensor for cyanide (CN- ) detection was synthesized and characterized via UV-vis and fluorescence spectroscopy. PBI exhibited a high sensitivity and rapid optical response for CN- due to the intramolecular charge transfer (ICT) mechanism. The detection limit of PBI for CN- was 1.15×10-7 M in the mixture of DMSO/H2 O (1 : 1, v/v). Moreover, probe PBI demonstrated high selectivity and sensitivity for CN- over other common anions, including Cl- , Br- , F- , I- , AcO- , ClO4 - , HSO4 - , SO4 2- , NO2 - , NO3 - and SCN- . This work provided a simple and effective approach to trace the toxic CN- ion with rapid response, high selectivity, and sensitivity that is possibly applied in environmental control and agricultural management.

A dual-channel chemosensor based on diarylethene bearing a benzoisothiazole unit for detecting CO32−

A new photochromic diarylethene with a benzoisothiazole unit has been designed and synthesized. The diarylethene could act as a colorimetric and fluorescence dual-channel chemosensor for CO32− with short response time, high selectivity, and excellent sensitivity. Moreover, the response mechanism of the chemosensor to CO32− was studied systematically in methanol. The chemosensor could be used to the detection of CO32− in practical water samples, and also be made into test papers for CO32− recognition with high efficiency.

Based on theoretical calculations designed a novel dual-channel chemo-sensor for Mg2+ and Zn2+ detection and bioimaging applications

Mg2+ and Zn2+ are essential metal ions for organism growth and development since they participate in various physiological metabolic processes and keep the body functioning normally. Realizing the efficient detection of these two metal ions is therefore crucial. In light of this background, we developed and synthesized a novel Schiff-based dual-channel fluorescein-derived chemo-sensor (FHBS) for the detection of Mg2+ and Zn2+ using theoretical calculations. The optimized experimental findings demonstrated that Mg2+ in DMSO/H2O (95/5, v/v, pH = 7.0, Tris-HCl) and Zn2+ in DMF/H2O (9/1, v/v, pH = 7.0, Hepes) may selectively elicit responses towards FHBS. Under the aforementioned optimization circumstances, the linear detection range of Mg2+ was from 0.4 to 7.0 μM, and for Zn2+, it was from 0.5 to 10.0 μM. The detection limits for Mg2+ and Zn2+ were calculated to be 0.40 μM and 0.65 μM, respectively. Finally, chemo-sensor (FHBS) was successfully applied in L929 cells and zebrafish live imaging. The experimental results demonstrated that FHBS can accurately detect Mg2+ and Zn2+ in organisms. Additionally, through cytotoxicity experiments, it was proved that the chemical sensor has good safety and biocompatibility.

A dual-channel chemosensor based on rhodamine and BODIPY conjugated dyad for ratiometric detection of Hg2+ and fluorescence on–off recognition of Cu2+ in aqueous solution and living cells

A dual-channel chemosensor based on rhodamine and BODIPY conjugated dyad for ratiometric detection of Hg2+ and fluorescence on–off recognition of Cu2+ in aqueous solution and living cells

Novel high sensitivity dual-channel chemosensor for detecting CN− based on asymmetric azine derivatives in aqueous media

A novel cyanide specifically selective and highly sensitive chemosensor HSD had been designed and synthesized. • The synthesis process of HSD is simple and environmentally friendly. • HSD is shown “naked-eye” and fluorescence “turn-off” response for CN − in solution. • It has been applied to monitor CN − in an aqueous solution. • The mechanism of action of HSD on CN − is the deprotonate. • A test strip of HSD was prepared to detect CN − quickly and easily. Specific monitoring of trace levels of poisonous ions by naked eyes is still a significant challenge in the surroundings. Herein, we developed a novel asymmetric azine dual-channel sensor (HSD) applied for selectively detecting the CN − in the aqueous media. The selectivity and sensitivity of sensor HSD for anions sensing were investigated by measuring the photophysical properties. The results show that HSD recognizes CN − with good selectivity and sensitivity, with an “off” fluorescence response and apparent color change (from colorless to yellow) under visible light and strong anti-interference to other common anions. According to fluorescence titration of sensor HSD to CN − , the detection limit was determined to be as low as 1.02 × 10 −8 M. In addition, the reaction mechanism of the probe has been studied by 1 H NMR titration and DFT theoretical calculations. Finally, the test strips were prepared and verified to be a convenient and high-efficiency test kit for detecting CN − by naked eyes in the actual sample.

A Novel High Selectivity Fluorimetric and Colorimetric Probe Based on Rhodamine B Hydrazide Derivatives for Detecting Hg2+ in Aqueous Media

A colorimetric and fluorescent dual-channel chemosensor (G1) with a simple structure was designed and synthesized to identify Hg2+ in an aqueous solution with high selectivity and sensitivity. After adding Hg2+, the color of G1 in the dimethyl sulfoxide (DMSO)/H2O (2:8, v/v) solution changed from colorless to a distinct rose red, whereas the fluorescence changed from colorless to bright orange under ultraviolet (UV) light. The detection limit on the fluorescence response of G1 to Hg2+ was as low as 6.09 × 10-7 mol/L. The results of the Job’s plot suggested that the combined stoichiometry between G1 and Hg2+ was 1:1. By successively adding Hg2+ and ethylenediaminetetraacetic acid (EDTA), the fluorescence process can be reversed and almost no fluorescence loss. In addition, G1-based test strips were produced and were able to qualitatively detect Hg2+ in tap water.

A dual-channel chemosensor based on 2-hydroxy-5-methyl-1,3-benzenedialdehyde for fluorescence detection and colorimetric recognition of glutamic acid

A colorimetric and fluorescent dual-channel glutamic acid (Glu) chemosensor 4-methyl-6-aldehyde-6′-methoxy-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol (AMS) bearing an aldehyde group has been designed and synthesized. This structurally simple chemosensor displays rapid response and high selectivity for Glu over other common amino acids in DMF/H2O (9: 1, v/v, buffered by 0.2 M Tris-phosphate buffer at pH = 7.0) solution. The chemosensor interacted with Glu to form intermolecular hydrogen bonds with significantly quenched fluorescence, switching from bright green fluorescence to no fluorescence. Moreover, AMS can also successfully detect glutamic acid by absorption spectroscopy, which exhibited an UV–vis spectrum change, while its color changed from pale yellow to colorless under natural light. The experimental results of the competitive amino acids revealed that chemosensor is highly selective for recognizing Glu without the interference of other amino acids. Job's plot indicates that the binding stoichiometry between the chemosensor AMS and the targeted amino acid Glu is 1:1. Hence, our experimental findings very strongly suggest that AMS can be used as chemosensor for detecting Glu in future.

Novel High Sensitivity Dual-Channel Chemosensor for Detecting Cn− Based on Asymmetric Azine Derivatives in Aqueous Media

Novel High Sensitivity Dual-Channel Chemosensor for Detecting Cn− Based on Asymmetric Azine Derivatives in Aqueous Media

A simple imine as a dual-channel chemosensor for detection of CN− and HS− ions via different mechanisms in organic and aquo-organic media

An imine based easy to make receptor (R) has been synthesized and characterized, which senses CN− and HS− ions selectively and sensitively in neat DMSO and H2O:DMSO (60:40 v/v) media. Upon treatment with these ions, the receptor exhibited instantaneous colour change from yellow to colourless and a fluorescence enhancement and these optical changes are easily detected by direct visualization. Further, other competitive anions didn’t display any observable colour and fluorescence changes, indicating the receptor's high selectivity towards CN− and HS− ions. The nucleophilic addition of cyanide ion to the imine bond induces an increase in fluorescence, while HS− ion triggered cleavage of the imine bond, producing enhancement in fluorescence in both the media. The limits of detection for CN− and HS− ions were calculated to be 0.9 and 0.7 μM, respectively, which are lower than the permissible limit of these ions in drinking water set by the World Health Organization (WHO). The receptor has fruitfully been applied for the detection of these ions in live HeLa cells.

A new dibenzothiophene-based dual-channel chemosensor for cyanide with aggregation induced emission

Based on dibenzothiophene fluorophore, a new colorimetric and fluorescent sensing material 2-(dibenzothiophenyl-4-ethenylidenyl)-1,3-indanedione (DTI) was developed, which was a favorable turn-off fluorescent sensor of monitoring CN– ion at extremely low detection limit (0.14 μM) in 99 % aq. DMSO solution. The response mechanism of DTI towards CN– could put down to nucleophilic attack of cyanide group (CN–) toward the double-bond between the dibenzothiophene and the 1,3-indanedione units, which breaking intramolecular charge transfer (ICT) process. This mechanism was proposed by 1H NMR, Job’s titration and DFT calculation, leading to a significant fluorescence attenuation and a visual color change. The absorption and emission experiments demonstrated that it showed highly sensitive, selective and good stability for CN– in DMSO/H2O (1:99, v/v). Moreover, DTI displayed high effectiveness in monitoring the CN– in test strips achieved to conveniently determinate CN– by naked-eye without any instruments.

A dual-channel chemosensor based on 8-hydroxyquinoline for fluorescent detection of Hg2+ and colorimetric recognition of Cu2+

A novel dual-channel chemosensor, 7-allylquinolin-8-ol (AQ), was synthesized based on 8-hydroxyquinoline for selective fluorescence detection of Hg2+ and colorimetric recognition of Cu2+. The chemosensor reacted with Hg2+ and generated a new Hg-containing compound with significantly enhanced fluorescence, which turned from faint blue to strong green. Further experiments indicated that AQ could be used to quantitatively detect Hg2+ via fluorescence spectroscopy with a low detection limit (2.1nM). The good reversibility of the synthesized chemosensor was also demonstrated using NaBH4. Moreover, AQ was successfully used for the detection of Cu2+ through the formation of a stable coordination compound, which exhibited an ultraviolet-visible (UV-Vis) ratiometric change, while its color changed from colorless to pale yellow under natural light. Additional experiments using various Cu2+ concentrations showed that the developed chemosensor could be further employed for the quantitative ratiometric estimation of Cu2+ by UV-Vis.

Understanding a Thermoemissive ESIPT-Based Solid-State Off–On Switch as a Dual-Channel Chemosensor in Solid and Solution Phases: Detailed Experimental and Theoretical Study

The excited-state intramolecular proton transfer (ESIPT)-assisted aggregation induced emission enhancement (AIEE) in an organic moiety (4-[(2,4-dihydroxy-benzylidene)-amino]-1,5-dimethyl-2-phenyl-1...

Catching S2− and Cu2+ by a highly sensitive and efficient salamo-like fluorescence-ultraviolet dual channel chemosensor

A highly sensitive and efficient fluorescence-ultraviolet dual channel chemical sensor H2L based on the salamo-like bisoxime (6,6′-dimethoxy-2, 2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) was synthesized, Cu2+ and S2− ions can be detected respectively. For the identification of metal cations, the Cu2+ can quench the fluorescence intensity of probe H2L at the excitation wavelength of 311 nm, and when the same equivalent of EDTA was added, the fluorescence intensity of L-Cu complex returned to its original intensity practically, completing the fluorescence “OFF-ON-OFF” cycle after adding the same amount of Cu2+ again. The mechanism was confirmed by high resolution mass spectrometry, and it was concluded that the probe H2L and Cu2+ formed a complex. For the identification of anions, UV–Vis spectral identification and naked-eye recognition for S2− were performed. The binding mode of the probe to the sulfur anion and the recognition mechanism were confirmed by 1H NMR titration. In addition, the probe H2L showed high selectivity and sensitivity to Cu2+ and S2−, the detection limits of L-Cu and L-S systems toward Cu2+ and S2− are 46 and 25 nM respectively. In terms of application, the content of Cu2+and S2− in different water samples (distilled water, Yellow River water and tap water) with probe H2L was successfully tested. These results indicated that the probe H2L can be used as a highly selective and sensitive dual channel sensor to detect both Cu2+ and S2− ions in the environment and biological systems.

Novel High Sensitivity Dual-Channel Chemosensor for Detecting CN- Based on Coumarin Derivative in Aqueous Media and Its Application in Food Samples

Novel High Sensitivity Dual-Channel Chemosensor for Detecting CN^- Based on Coumarin Derivative in Aqueous Media and Its Application in Food Samples

The BODIPY-Based Chemosensor for Fluorometric/Colorimetric Dual Channel Detection of RDX and PA.

A fluorometric/colorimetric dual-channel chemosensor based on a hydrazine-substituted BODIPY probe has been successfully fabricated for the detection of RDX and PA. The chemosensor displays turn-on fluorescence behavior upon RDX with a detection limit of 85.8 nM, while showing a turn-off response to PA with a detection limit of 0.44 μM. Meanwhile, an obvious color difference is observed by the naked-eye after the reaction for RDX. Thus, in application, a two-to-two logic gate is constructed for potential application in explosives detection. Additionally, portable equipment is also developed for in situ determination of RDX.

Naphthoquinone-Based Colorimetric and Fluorometric Dual-Channel Chemosensor for the Detection of Fe2+ Ion and Its Application in Bio-Imaging of Live Cells and Zebrafish

A new naphthoquinone-based chemosensor 2-((3-hydroxyphenyl)amino)-3-(phenylthio)naphthalene-1,4-dione (2HPN) was successfully synthesized for the selective detection of Fe2+. The sensing property o...

A new dibenzothiophene-based dual-channel chemosensor for cyanide with aggregation induced emission

A new dibenzothiophene-based barbituric acid derivative (DTB) with an aggregation induced emission (AIE) effect was synthesized as a naked-eye colorimetric and fluorescent probe for CN−.

An acid-fluorescence and alkali-colorimetric dual channels sensor for Hg2+ selective detection by different coordination manners in aqueous media

Due to the advantages of high selectivity, accuracy and mutual calibration, dual-channel sensors have drawn much attention. In this work, a water-soluble fluorescence and colorimetric dual-channel chemosensor (AAT) with both azomonardine and aminothiazole units has been designed and synthesized. ArOH and N groups, which respectively belonged to azomonardine and thiazole unit, exhibited pH dependent ionization, which leaded AAT exhibiting strong naked-eye visible fluorescence and color in acidic and alkaline solution, respectively. When N was ionized in acidic solution, fluorescence was turned on. The colorimetry occurred while the ionization of Ar−OH in alkaline solution. Moreover, the solution pH had a significant impact on the binding efficiency between AAT and Hg2+, resulted in different coordination manners and stoichiometry. At pH 5.0, in the fluorescence channel, the stoichiometry of AAT for Hg2+ was calculated as 1:2 and the linear detection concentration was ranged from 0 to 35 μM. It was in a range of 0–12 μM through colorimetric method with the stoichiometry of 1:1 at pH 7.5. Furthermore, neither in fluorescence or in colorimetric channel, AAT showed high specificity toward Hg2+ among numerous cationic and anion ions. Also, AAT realized the Hg2+ identification and determination in river water samples.