Novel Coumarin-based Fluorescent Probe for Selective Detection of Bisulfite Anion in Water

A mitochondrial targeted dual ratiometric near-infrared fluorescent probe based on ICT effect for the detection of SO2 derivative and its bioimaging

SO2 derivatives play an important role in many metabolic processes, excessive ingestion of them can lead to serious complications of various diseases. In this work, a novel dual ratiometric NIR fluorescent probe XT-CHO based on ICT effect was synthesized for detecting SO2 derivative. In the design of the probe, the α, β-unsaturated bond formed between benzopyran and coumarin was used as the reaction site for SO2, meanwhile, the extended π-conjugate system promoted maximum emission wavelength of the probe up to 708 nm. Notably, the probe exhibited high selectivity and sensitivity for detecting SO2, the limit of detection reached 2.13 nM and 58.5 nM in fluorescence spectra and UV-Vis absorption spectra, respectively. The reaction mechanism of SO2 and XT-CHO had been verified by 1H NMR, ESI-MS spectra and DFT calculation. Moreover, the probe was successfully applied in detecting endogenous and exogenous SO2 in living cells and proved possessed the mitochondrial targeted ability.

A quinoline-based probe for the ratiometric fluorescent detection of sulfite in lysosomes of living cells

A lysosome-targeting ratiometric fluorescent probe was synthesized for detecting sulfite based on sulfite-triggered nucleophilic addition reaction. Due to the specific reaction, the fluorescence intensity ratio (I₅₃₀/I₃₉₀) of the probe in an almost aqueous solution (0.5% DMSO) changed significantly after the addition of HSO₃^-, corresponding to the change in the fluorescence color of the solution from green to blue. The recognition was conducted using high-resolution mass spectrometry, proton nuclear magnetic resonance, and density functional theory calculations. The fluorescent probe could be utilized to quantitatively monitor HSO₃^- in lysosomes of living C6 glioma cells and real-water samples.

Fluorescent-based nanosensors for selective detection of a wide range of biological macromolecules: A comprehensive review

Thanks to their unique attributes, such as good sensitivity, selectivity, high surface-to-volume ratio, and versatile optical and electronic properties, fluorescent-based bioprobes have been used to create highly sensitive nanobiosensors to detect various biological and chemical agents. These sensors are superior to other analytical instrumentation techniques like gas chromatography, high-performance liquid chromatography, and capillary electrophoresis for being biodegradable, eco-friendly, and more economical, operational, and cost-effective. Moreover, several reports have also highlighted their application in the early detection of biomarkers associated with drug-induced organ damage such as liver, kidney, or lungs. In the present work, we comprehensively overviewed the electrochemical sensors that employ nanomaterials (nanoparticles/colloids or quantum dots, carbon dots, or nanoscaled metal-organic frameworks, etc.) to detect a variety of biological macromolecules based on fluorescent emission spectra. In addition, the most important mechanisms and methods to sense amino acids, protein, peptides, enzymes, carbohydrates, neurotransmitters, nucleic acids, vitamins, ions, metals, and electrolytes, blood gases, drugs (i.e., anti-inflammatory agents and antibiotics), toxins, alkaloids, antioxidants, cancer biomarkers, urinary metabolites (i.e., urea, uric acid, and creatinine), and pathogenic microorganisms were outlined and compared in terms of their selectivity and sensitivity. Altogether, the small dimensions and capability of these nanosensors for sensitive, label-free, real-time sensing of chemical, biological, and pharmaceutical agents could be used in array-based screening and in-vitro or in-vivo diagnostics. Although fluorescent nanoprobes are widely applied in determining biological macromolecules, unfortunately, they present many challenges and limitations. Efforts must be made to minimize such limitations in utilizing such nanobiosensors with an emphasis on their commercial developments. We believe that the current review can foster the wider incorporation of nanomedicine and will be of particular interest to researchers working on fluorescence technology, material chemistry, coordination polymers, and related research areas.

A mitochondria-targeting ratiometric fluorescent probe for the detection of sulfur dioxide in living cells

A mitochondria-targeting ratiometric fluorescent probe was developed for the detection of sulfur dioxide in living cells.

A novel coumarin-derived dithioacetal chemosensor for trace detection of Hg2+ in real water samples

A novel coumarin-derived dithioacetal chemosensor, 8-(1,3-dithian-2-yl)-7-hydroxy-4-methylcoumarin (LS), has been designed and synthesized. The sensor LS showed highly selective fluorescent sensing for Hg2+ with a low detection limit of 0.81 nM in the pH range from 6.15 to 9.96 in ethanol/water (1:1, v/v) solution. The sensing mechanism of LS toward Hg2+ was proposed and verified by 1H nuclear magnetic resonance spectroscopy studies. Under an ultraviolet lamp, the fluorescence color changes could be easily detected by the naked eye. In addition, the sensor LS has been applied in the trace detection of Hg2+ in real water samples.

A Benzopyronin-Based Two-Photon Fluorescent Probe for Ratiometric Imaging of Lysosomal Bisulfite with Complete Spectral Separation

Bisulfite (HSO₃^-), which equilibrates with sulfite (SO₃^2-) and sulfur dioxide (SO₂) in aqueous media, can be produced endogenously during oxidation of hydrogen sulfide or sulfur-containing amino acids. Lysosomes, known as the scavengers of living cells, play a crucial role in the metabolic process, and bisulfite is often produced inside the lysosomes. Therefore, detection of bisulfite in lysosomes is a subject of significant interest. Herein, we disclose a lysosome-targeting, two-photon excitable, and ratiometric signaling (near-infrared/green) fluorescent probe that detects bisulfite through a fast 1,6-conjugate addition reaction. The probe shows excellent selectivity toward bisulfite over other biologically relevant species. Notably, the probe allows ratiometric fluorescence imaging of lysosomal bisulfite with complete spectral separation under one-photon as well as two-photon excitation conditions.

A FRET based ratiometric fluorescent probe for detection of sulfite in food

A new fluorophore pyrido[1,2-a]benzimidazole based ratiometric fluorescent probe for the selective detection of sulfite ions in water was investigated.

Reversible Ratiometric Fluorescent Probe for Sensing Bisulfate/H2O2 and Its Application in Zebrafish

Herein, a novel near-infrared fluorescent probe for ratiometric detection of bisulfate was designed and developed based on a conjugation of naphthopyran-benzothiazolium system. The sensor showed excellent selectivity, high sensitivity and a rapid response toward bisulfite in aqueous solution. Upon the addition of HSO₃^-, the sensor displayed 37-fold (I₅₂₀/I₆₃₀) fluorescence intensity enhancement, accompanied by an apparent color change from violet to colorless, suggesting that the sensor can be used to detect HSO₃^- with "naked-eye". Notably, the addition product can be applied to the design of regenerative chemodosimeters based on the H₂O₂ promoted elimination of bisulfite and recovery of probe 1. Further cell and zebrafish imaging experiment demonstrated that the sensor could image the bisulfite/H₂O₂ redox cycle in biological system with ratiometric manners.

A ratiometric fluorescent probe for sensing sulfite based on a pyrido[1,2-a]benzimidazole fluorophore

A ratiometric fluorescent probe for sensing SO₃²⁻ based on a new pyrido[1,2-a]benzimidazole fluorescent dye was synthesized.

A self-assembled fluorescent organic nanoprobe and its application for sulfite detection in food samples and living systems

An AIEE-based nanoprobe has been rationally developed for detection of sulfite in food samples and living systems with excellent selectivity and an extremely low detection limit.

Reaction-based probe for hydrogen sulfite: dual-channel and good ratiometric response

We designed and synthesized a new series of intramolecular charge transfer (ICT) molecules (compounds T1, T2 and T3) by attaching various electron-donating thiophene groups to the triphenylamine backbone with aldehyde group as the electron acceptor. Based on the nucleophilic addition reaction between hydrogen sulfite and aldehyde, all compounds could act as ratiometric optical probe for hydrogen sulfite and displayed efficient chromogenic and fluorogenic signaling. Upon the addition of hydrogen sulfite anions, probe T3 displayed apparent fluorescent color changes from yellowish-green to blue, with a large emission wavelength shift (Δλ = 120 nm). T3 responded to hydrogen sulfite with high sensitivity and the detection limit was determined to be as low as 0.9 μM. At the same time, apparent changes in UV-vis spectra could also be observed. By virtue of the special nucleophilic addition reaction with aldehyde, T3 displayed high selectivity over other anions. Copyright © 2016 John Wiley & Sons, Ltd.

A novel carbazole-based mitochondria-targeted ratiometric fluorescent probe for bisulfite in living cells

A novel carbazole–indolium based mitochondria-targeted ratiometric fluorescent probe was developed, which could selectively respond to bisulfite among other sulfur-containing species in living cells.

An A–π–A′ structural ratiometric fluorescent probe based on benzo[e]indolium for bisulfite and its application in sugar samples and living cells

An A–π–A′ structural ratiometric fluorescent probe 1 bearing a benzo[e]indolium moiety was developed for the detection of HSO₃⁻ in PBS buffer solution.

A new diketopyrrolopyrrole-based probe for sensitive and selective detection of sulfite in aqueous solution

A new probe was synthesized by incorporating an α,β-unsaturated ketone to a diketopyrrolopyrrole fluorophore. The probe had exhibited a selective and sensitive response to the sulfite against other thirteen anions and biothiols (Cys, Hcy and GSH), through the nucleophilic addition of sulfite to the alkene of probe with the detection limit of 0.1 μM in HEPES (10 mM, pH 7.4) THF/H2O (1:1, v/v). Meanwhile, it could be easily observed that the probe for sulfite changed from pink to colorless by the naked eye, and from pink to blue under UV lamp after the sulfite was added for 20 min. The NMR and Mass spectral analysis demonstrated the expected addition of sulfite to the C=C bonds.

BODIPY-based colorimetric/ratiometric fluorescence probes for sulfite in aqueous solution and in living cells

Two colorimetric/ratiomrtric fluorescence probes for sulfite utilizing the Michael-addition mechanism were designed. BSP1 could be applied in the imaging of sulfite in living cells.

A real-time colorimetric and ratiometric fluorescent probe for rapid detection of SO2 derivatives in living cells based on a near-infrared benzopyrylium dye

Near-infrared benzopyrylium dye was employed as a fast-responding ratiometric fluorescent probe for sensitive and selective detection of SO₂ derivatives in 100% aqueous solution as well as in living cells.

Selective, highly sensitive fluorescent probe for the detection of sulfur dioxide derivatives in aqueous and biological environments

On the basis of a unique nucleophilic addition reaction, a novel water-soluble broadly emitting (500-700 nm) fluorescent Probe 1 was developed for the rapid detection of SO2 derivatives in aqueous media. The positively-charged benzopyrylium moiety in Probe 1 provides both excellent water solubility, making this probe applicable in 100% aqueous environments, and the ability to function as a fluorescence quencher of the coumarin moiety. Probe 1 generates a nearly instantaneous strong fluorescence signal in response to SO2 derivatives having an 8.3 nM detection limit for bisufite. The resulting Probe 1-sulfite adduct emits in the green/red spectral region (λ(max) = 585 nm) with a large Stokes shift (139 nm). The probe exhibits excellent selectivity toward SO2 derivatives over other potential interfering agents including reactive sulfur-containing species. Importantly, we demonstrate that Probe 1 can be used for the real-time sensing and bioimaging of SO2 derivatives in living cells.

Determination of gaseous sulfur dioxide and its derivatives via fluorescence enhancement based on cyanine dye functionalized carbon nanodots

The development of convenient methods for sulfur dioxide and its derivatives analysis is critically important because SO2 causes worldwide serious environmental problems and human diseases. In this work, we show an unprecedented example of an energy-transfer-based fluorescence nanoprobe for selective and quantitative detection of SO2, through molecular engineering of the fluorescent carbon nanodots by a cyanine dye which have a unique reactivity to bisulfite, achieving a detection limit of 1.8 μM with a linear relationship (R(2) = 0.9987). The specific detection was not interfered with other potential coexisted species. In addition, the probe is demonstrated for the determination of SO2 gas in aqueous solution as well as for visually monitoring of SO2 gas in air. This nanomaterial based probe is easily prepared, fast responding, and thus potentially attractive for extensive application for the determination of SO2 and other similar air pollutants.

Ratiometric fluorescent probe for rapid detection of bisulfite through 1,4-addition reaction in aqueous solution

A ratiometric fluorescent probe based on a positively charged benzo[e]indolium moiety for bisulfite is reported. The bisulfite underwent a 1,4-addition reaction with the C-4 atom in the ethylene group. This reaction resulted in a large emission wavelength shift (Δλ = 106 nm) and an observable fluorescent color change from orange to cyan. The reaction could be completed in 90 s in a PBS buffer solution and displayed high selectivity and sensitivity for bisulfite. A simple paper test strip system was developed to detect bisulfite rapidly. Probe 1 was used to detect bisulfite in real samples with good recovery.

Fluorescent probes for hydrogen sulfide detection and bioimaging

In this feature article, we address the synthesis and design strategies for the development of fluorescent probes for H₂S, based on the reaction type between H₂S and the probes.

Selective and sensitive chromofluorogenic detection of the sulfite anion in water using hydrophobic hybrid organic-inorganic silica nanoparticles

In water and wine: Chromofluorogenic detection of the sulfite anion in pure water was accomplished by using a new hybrid organic-inorganic material that contained a probe entrapped in hydrophobic biomimetic cavities. This material was used for the detection of sulfite in red wine.

A fluorescent turn-on probe for bisulfite based on hydrogen bond-inhibited C=N isomerization mechanism

A fluorescence turn-on probe for bisulfite has been developed by taking advantage of the specific reaction of bisulfite and aldehyde in combination with the hydrogen bond inhibited C=N isomerization mechanism. The practical value of this selective and sensitive fluorescent probe was confirmed by its application to detection of bisulfite in granulated sugar.

A ratiometric fluorescent probe for bisulphite anion, employing intramolecular charge transfer

4-(1H-benzimidazol-2-yl)benzaldehyde (1) has been developed as a new ratiometric fluorescent probe for bisulphite, based on the modulation of intramolecular charge transfer (ICT). Upon mixing with bisulphite in aqueous ethanol, an aldehyde-bisulphite adduct was formed and the ICT of the probe was switched off, which resulted in a ratiometric fluorescence response with an enhancement of the ratios of emission intensities at 368 and 498 nm. The detection range of the probe for bisulphite is in the 2.0-200 µmol/L concentration range and the detection limit is 0.4 µmol/L. Probe 1 produces a ratiometric fluorescent response to bisulphite with a marked emission wavelength shift (130 nm) and displays high selectivity for bisulphite over other anions.