Colorimetric Fluorescent Probe Research Articles

A Colorimetric Fluorescent Probe for SO2 Derivatives-Bisulfite and Sulfite at Nanomolar Level.

A colorimetric fluorescent probe with fluorescence emission feature sensitive to SO2 derivatives, i.e. bisulfite (HSO3-) and sulfite (SO32-), was developed based on the HSO3-/SO32--mediated nucleophilic addition reaction of the probe that. This probe exhibited SO32- sensing ability with detection limit down to 46nM and desired selectivity over other reference anions and redox species. The preliminary fluorescence bioimaging experiments have validated the practicability of the as-prepared probe for SO2 derivatives sensing in living cells.

New pyrazolo-quinoline scaffold as a reversible colorimetric fluorescent probe for selective detection of Zn 2+ ions and its imaging in live cells

Abstract A simple colorimetric fluorescent chemosensor 1-[5-(2-chloro-6-methylquinolin-3-yl)-3-(2-hydroxyphenyl)-4,5-dihydro- 1H -pyrazol-1-yl]ethan-1-one ( L ) based on pyrazoline has been designed, synthesized and characterized. The sensing properties of L were studied using UV–visible and fluorescence spectrophotometric analyses. L showed excellent selectivity towards Zn 2+ ions over other metal ions in aqueous media through “OFF-ON” type process and a possible photoinduced electron transfer (PET). The viability of L to Zn 2+ has been demonstrated by live cell imaging.

A dual-emission probe to detect moisture and water in organic solvents based on green-Tb3+ post-coordinated metal-organic frameworks with red carbon dots.

Using p-phenylenediamine as a precursor, p-carbon dots (p-CDs) with strong red-light emission were encapsulated into a metal-organic framework (MOF) followed by introduction of green light-emitting Tb3+ to form a two-color light-emitting hybrid (Tb3+@p-CDs/MOF). The as-prepared fluorescent-functionalized MOF not only maintained the excellent optical properties of p-CDs and Tb3+ to give strong emission, but also had good chemical and physical properties. The chosen p-CDs were aggregated readily in water, which led to only very weak photoluminescence, whereas the opposite effect was noted in the organic solvents ethanol, dimethylformamide and cyclopropane. Therefore, the as-prepared hybrid showed different color light emission in water or organic solvents, and acted as a ratiometric and colorimetric fluorescent probe to detect water content in organic solvents. Moreover, this hybrid also served as a ratiometric luminescent sensor for detection of relative humidity (RH): the ratio of light intensity at 545 nm to that at 605 nm increased linearly with increasing RH from 33.0% to 85.1% in the atmosphere.

A near-infrared and colorimetric fluorescent probe for palladium detection and bioimaging

A near-infrared (NIR) and colorimetric fluorescent probe was developed for palladium species via a palladium catalyzed deallylation reaction. In this probe, 6-hydroxy-2,3-dihydro-xanthene-indolium (CyH) was acted as the signal unit and an allyl carbonate group was acted as the recognition unit. This non-fluorescent probe molecule can release the relevant fluorophore after interaction with palladium. The sensing mechanism was investigated by optical spectrum and NMR spectra. The probe can be used for “naked-eye” detection of palladium, and exhibited high selectivity to palladium over various other metal ions. Furthermore, the probe can be applied to imaging intracellular palladium ions in living HeLa cells, indicating its great potential for in vivo bioanalytical applications.

Two colorimetric fluorescent probes for detection Fe3+: Synthesis, characterization and theoretical calculations

Two novel rhodamine-based fluorescent probe were designed and synthesized. The probes exhibited highly selective and sensitive recognition toward Fe3+ over other metal ion. In addition, the optical sensor features and the detection limit of probes for Fe3+ were investigated. Beside, we performed quantum calculations for understanding the reaction mechanism between probes and Fe3+.

A novel coumarin-based fluorescence enhancement and colorimetric probe for Cu2+ via selective hydrolysis reaction

Abstract A new colorimetric fluorescent probe, 3-benzothiazolyl-coumarin-7-yl picolinate (P1), based on coumarin derivative has been designed and synthesized to detect Cu2+ in CH3CN-water (1:1,v/v) solution. The probe showed highly selective and sensitive fluorescence enhancement response towards Cu2+ via selective hydrolysis reaction of the picolinate moiety followed by generating a strongly fluorescent 3-benzothiazolyl-7-hydroxycoumarin (2) moiety, whereas other competing metal cations (Na+, K+, Mg2+, Ag+, Fe3+, Pb2+, Mn2+, Ca2+, Ni2+, Cr3+, Zn2+, Sn2+, Hg2+, Al3+, Pd2+, Pt2+, Co2+, Au3+) did not possess the property. Upon the addition of Cu2+, the color of P1 changed from colorless to yellow-green, and gave an emission at around 470 nm. Moreover, the detection limit toward Cu2+ was calculated to be as low as 23.9 nM.

A new water-soluble and colorimetric fluorescent probe for highly sensitive detection of organophosphorus pesticides

A new water-soluble fluorescent probe bearing 1,8-naphthalimide dye, a quaternary ammonium salt and a boronate group was developed for the detection of organophosphorus pesticides.

Fabrication and application of a ratiometric and colorimetric fluorescent probe for Hg2+ based on dual-emissive metal–organic framework hybrids with carbon dots and Eu3+

A novel ratiometric and colorimetric PL probe was designed and prepared to detect Hg2+ in an aqueous environment by encapsulating excellent PL CDs and Eu3+ into MOF-253.

Semicarbazide-based naphthalimide as a highly selective and sensitive colorimetric and “turn-on” fluorescent chemodosimeter for Cu2+

A semicarbazide-based naphthalimide was designed and synthesized as a colorimetric fluorescent probe. Upon reaction with Cu2+ in a buffer solution of pH 7.4 (buffer water/acetonitrile=80:20, v/v), the probe exhibits color changes from colorless to jade-green accompanying remarkable enhancement in its fluorescence, which could be mechanistically ascribed to the Cu2+-promoted hydrolysis of the semicarbazide moiety leading to the release of the green fluorescent 4-amino-1,8-naphthalimide fluorophore. The probe also displayed excellent performance in high sensitivity as well as good selectivity for Cu2+ over other metallic cations.

Novel Tumor-Specific and Mitochondria-Targeted near-Infrared-Emission Fluorescent Probe for SO2 Derivatives in Living Cells

Endogenous sulfur dioxide (SO2) is an important gaseous signal molecule, which was also regarded as one of the reactive sulfur spaces (RSS) and closely related to cardiovascular diseases and many neurological disorders. However, the design and synthesis of fluorescent probes with near-infrared-emission which can detect mitochondrial SO2 and its derivatives in living cells still remain unresolved. Herein, a biotin and coumarin-benzoindole conjugate BCS-1 was presented as a ratiometric and colorimetric fluorescent probe for tracing SO2 derivatives with excellent selectivity and rapid responsibility. Notably, it is the first mitochondria-targeted near-infrared-emission probe that could selectively detect SO2 in tumor cells. BCS-1 could selectively enter into mitochondria of tumor cells, and the detection limit for SO2 derivatives was determined as 72 nM.

A novel fluorescent sensor derived from benzimidazo[2,1-a]benz[de]isoquinoline-7-one-12-carboxylic acid for Cu2+, Cd2+ and PPi

Fluorescent sensor of N,N-bis(pyridin-2-ylmethyl)benzimidazo[2,1-a]benz[de]isoquinoline-7-one-12-carboxamide (L) was prepared. L not only showed fluorescence quenching towards Cu2+ with a detection limit of 1.2 × 10−8 mol/L in acetonitrile–H2O (9:1) buffer solution, but also showed fluorescence turn-on response with a blue shift towards Cd2+ with a detection limit of 1.5 × 10−7 mol/L in the same condition. Moreover, the new formed [Cu(L)] complex was found to act as a selective ‘turn-on’ fluorescent probe for pyrophosphate (PPi) with detection limit of 8 × 10−9 mol/L, and [Cd(L)] complex was found to act as a selective colorimetric fluorescent probe for PPi with detection limit of 2.4 × 10−8 mol/L. Such behaviors confirmed L could be applied as fluorescent sensor to detect Cu2+, Cd2+ and PPi based on different mechanisms. The different binding mode and sensing mechanism of L with Cu2+ and Cd2+ was verified by DFT/TDDFT calculation using Gaussian 09.

A near-infrared fluorescent probe for rapid detection of hydrogen peroxide in living cells

A new near-infrared and colorimetric fluorescent molecular probe was developed for rapid detection of H2O2. The near-infrared fluorescence OFF–ON switch is triggered by transformation of phenylboronic acid unit to phenol in the presence of H2O2. No quinone methides are released in this process, which is preferable for in vivo studies. In addition, probe 1 at low concentration exhibits high quality optical imaging during a short period in in vitro cell study.

Synthesis and evaluation of a new colorimetric and ratiometric fluorescence probe for copper ions

Synthesis and spectroscopic evaluation of compounds 3a, 3b and 4 reveal that cone conformer of 25,27-bis(o-aminothiophenyl propyloxy) -tetra-p-tert-butylcalix[4]arene 3a can function as a highly selective ratiometric and colorimetric fluorescence probe for copper ions.

Ratiometric and colorimetric detection of hydrogen sulfide with high selectivity and sensitivity using a novel FRET-based fluorescence probe

With recognition of the biological significance of H2S, we have designed and synthesized a novel ratiometric and colorimetric fluorescence probe, CR-DNP based on a H2S induced thiolysis reaction as well as the fluorescence resonance energy transfer process. It displayed some desirable properties, such as good photostability, high selectivity and excellent sensitivity. Also, a considerably fluorescence enhancement (15-fold) and distinct visible color change (colorless to bright orange) was observed. A good linear relationship between the emission intensity ratios and NaHS concentrations suggested that it can detect H2S quantitatively with a detection limit as low as 0.4 μM. Furthermore, due to its biocompatibility, the sensor could easily permeate through the cell membrane and trace the intracellular H2S levels change.

A coumarin-based colorimetric fluorescent probe for hydrogen sulfide

A coumarin-based fluorescent probe for selective detection of hydrogen sulfide (H2S) is presented. This ‘off–on’ probe exhibited high selectivity towards H2S in aqueous solution with a detection limit of 30 nM. Notably, because of its dual nucleophilicity, the probe could avoid the interference of thiols and other sulfur containing compounds. A novel coumarin-based, reaction-type fluorescent probe for detection of H2S in aqueous solution was synthesized through a two-step nucleophilic reaction.

An azodye-rhodamine-based fluorescent and colorimetric probe specific for the detection of Pd(2+) in aqueous ethanolic solution: synthesis, XRD characterization, computational studies and imaging in live cells.

Azodye-rhodamine hybrid colorimetric fluorescent probe (L) has been designed and synthesized. The structure of L has been established based on single crystal XRD. It has been shown to act as a selective turn-on fluorescent chemosensor for Pd(2+) with >40 fold enhancement by exhibiting red emission among the other 27 cations studied in aqueous ethanol. The coordination features of the species of recognition have been computationally evaluated by DFT methods and found to have a distorted tetrahedral Pd(2+) center in the binding core. The probe (L) has been shown to detect Pd up to 0.45 μM at pH 7.4. Furthermore, the probe can be used to image Pd(2+) in living cells.

A bifunctional colorimetric fluorescent probe for Hg(2+) and Cu(2+) based on a carbazole-pyrimidine conjugate: chromogenic and fluorogenic recognition on TLC, silica-gel and filter paper.

A bifunctional fluorescent probe based on a carbazole-pyrimidine conjugate for Hg(2+) and Cu(2+) detection was designed and synthesized. Probe 3 exhibits red shifts in its absorption and fluorescence spectra with significant visual color changes in the presence of these ions. The detection limits of probe 3 for these metal ions were in the nanomolar range. The probe could also be useful as a solid optical sensor for Hg(2+) and Cu(2+).

A dual-mode chemosensor: Highly selective colorimetric fluorescent probe for Cu2+ and F− ions

N-Phenylthiosemicarbazones (R1–R4) have been synthesized and characterized by various spectroscopic techniques. The sensors (R1–R4) exhibited highly selective and sensitive recognition toward Cu2+ and F− ions over other cations and anions via visual color change. Sensors showed a significant fluorescent enhancement toward Cu2+ in aqueous medium and found a sub-nanomolar detection limit with good quantum yield. R1 displayed high selectivity to Cu2+ over other interference ions with 89-fold fluorescence intensity enhancement upon the addition of 2equiv. of Cu2+. In addition, the turn-on fluorescent changes upon the addition of Cu2+, is also applied in cell imaging.

Detection of HSO₄⁻ ion based on the hydrolysis of diketopyrrolopyrrole-derived Schiff base with chromogenic and fluorogenic dual signals.

A new diketopyrrolopyrrole-based Schiff base L was synthesized and its anion sensing behavior was explored. L showed exclusive response toward HSO4(-) ion and also distinguished HSO4(-) from other anions by color changes (from dark red to orange) and 21 fold fluorescence enhancement at 370 nm in aqueous solution (THF/H2O = 8/1, v/v). The sensing mechanism was suggested to proceed via a hydrolysis process. The results provided colorimetric and fluorimetric assays to selectively detect the presence of a HSO4(-) over a wide range of other interfering anions. The results could potentially be used as a dual colorimetric-fluorescent probe for monitoring HSO4(-) levels in physiological and environmental systems.

Naphthylamine–Rhodamine-Based Ratiometric Fluorescent Probe for the Determination of Pd2+ Ions

A naphthylamine-rhodamine hybrid ratiometric and colorimetric fluorescent probe (RN) was designed and synthesized. RN can identify Pd(2+) ions with high selectivity and sensitivity. Furthermore, the probe can be used to monitor Pd(2+) ions in live mice by fluorescence imaging.