Selective Ratiometric Fluorescent Probe Research Articles

A highly selective ratiometric two-photon fluorescent probe for human cytochrome P450 1A1 and its application

A highly selective ratiometric two-photon fluorescent probe for human cytochrome P450 1A1 and its application

Highly selective ratiometric fluorescent probe based on diketopyrrolopyrrole for Au3+: an experimental and theoretical study

A diketopyrrolopyrrole-based fluorescent probe 1 was explored as a ratiometric probe for selective detection of Au3+, with the detection limit of 18 nM.

A highly selective ratiometric fluorescent probe for the cascade detection of Zn2+ and H2PO4− and its application in living cell imaging

A simple ratiometric sensor (L1) for the cascade detection of Zn2+ and H2PO4− with high selectivity was reported based on the intermolecular charge transfer (ICT) mechanism.

A two-photon ratiometric ESIPT probe for the discrimination of different palladium species and its application in bioimaging.

A highly selective ratiometric ESIPT fluorescent probe has been designed for the detection of palladium species of all the typical oxidation states (0, +2, +4). The probe exhibits a ratiometric fluorescence response towards the palladium species in about 20 min at room temperature based on the excited state intramolecular proton transfer (ESIPT) process. Moreover, the probe can discriminate different palladium species (Pd0, Pd2+, Pd4+) under different detection conditions. Furthermore, the probe can be used to quantitatively detect palladium in drinking water with a low detection limit (15.6 nM, 1.66 ppb). Additionally, it could be used as a two-photon palladium probe for bioimaging with low cytotoxicity and autofluorescence.

A highly selective ratiometric fluorescent probe for biothiol and imaging in live cells

A new N-butyl-4-amino-1,8-naphthalimide-based colorimetric and ratiometric fluorescent probe for the detection of biothiols (cysteine, homocysteine, and glutathione) was designed and synthesized.

A highly selective ratiometric fluorescent probe for the sensitive detection of hypochlorous acid and its bioimaging applications

A rapid-response, highly selective and ratiometric fluorescent probe was synthesized to sensitively detect HOCl in living cells.

A Highly Selective Ratiometric Two-Photon Fluorescent Probe for Human Cytochrome P450 1A.

Cytochrome P450 1A (CYP1A), one of the most important phase I drug-metabolizing enzymes in humans, plays a crucial role in the metabolic activation of procarcinogenic compounds to their ultimate carcinogens. Herein, we reported the development of a ratiometric two-photon fluorescent probe NCMN that allowed for selective and sensitive detection of CYP1A for the first time. The probe was designed on the basis of substrate preference of CYP1A and its high capacity for O-dealkylation, while 1,8-naphthalimide was selected as fluorophore because of its two-photon absorption properties. To achieve a highly selective probe for CYP1A, a series of 1,8-naphthalimide derivatives were synthesized and used to explore the potential structure-selectivity relationship, by using a panel of human CYP isoforms for selectivity screening. After screening and optimization, NCMN displayed the best combination of selectivity, sensitivity and ratiometric fluorescence response following CYP1A-catalyzed O-demetylation. Furthermore, the probe can be used to real-time monitor the enzyme activity of CYP1A in complex biological systems, and it has the potential for rapid screening of CYP1A modulators using tissue preparation as enzyme sources. NCMN has also been successfully used for two-photon imaging of intracellular CYP1A in living cells and tissues, and showed high ratiometric imaging resolution and deep-tissue imaging depth. In summary, a two-photon excited ratiometric fluorescent probe NCMN has been developed and well-characterized for sensitive and selective detection of CYP1A, which holds great promise for bioimaging of endogenous CYP1A in living cells and for further investigation on CYP1A associated biological functions in complex biological systems.

A highly selective and sensitive ratiometric fluorescent probe for pH measurement based on fluorescence resonance energy transfer

Fluorescein-rhodamine 6G(Flu-Rh) was synthesized and used as the fluorescence probe for pH measurement based on fluorescence resonance energy transfer(FRET). In the probe, fluorescein fluorophore and pH-sensitive rhodamine 6G hydrazide were used as FRET donor and acceptor, respectively. The values of acidity constant(pK a) and fluorescence quantum yield(Φ) of Flu-Rh were 3.71 and 0.72, respectively. The fluorescence efficiency of Flu-Rh remains almost constant when the pH value of the sample solution changed 10 times in a range of 4.78–7.03 continuously. The present probe is simple and easy-to-use for the pH measurement in acidic media.

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.

A highly selective ratiometric bifunctional fluorescence probe for Hg(2+) and F(-) ions.

A triarylborane derivative BN-S, which contains a Hg(2+)-responsive dithioacetal group and a F(-)-responsive boryl group, has been designed and synthesized via the functionalization of 2-dimesitylboryl-2'-(N,N-dimethylamino)biphenyl core skeleton with a dithioacetal substituent. This compound displays intense intramolecular charge transfer fluorescence, even for its nano-aggregates in water. The Hg(2+)-promoted deprotection of the dithioacetal group and complexation of F(-) with the tri-coordinate boron center cause hypochromism of fluorescence to different extents. And thus BN-S behaves as a promising ratiometric bifunctional fluorescence probe to detect Hg(2+) and F(-) simultaneously. In addition, the detection of Hg(2+) is performable in aqueous medium using its nano-aggregates.

A highly sensitive, selective ratiometric fluorescent probe for cobalt(II) and its applications for biological imaging.

Probe has been developed as the first ratiometric fluorescent cobalt probe with high sensitivity and selectivity based on internal charge transfer (ICT). Most importantly, the probe achieved the imaging and detection of cobalt in cells with ratiometric measurement.

A ratiometric rhodamine–naphthalimide pH selective probe built on the basis of a PAMAM light-harvesting architecture

PAMAM light harvesting antenna of second generation was synthesized and investigated. Novel compound was configured as a wavelength-shifting bichromophoric molecule where the system surface is labeled with yellow-green emitting 4-(N,N-dimethylamino)ethylamino-1,8-naphthalimide “donor” units capable of absorbing light and efficiently transferring the energy to a focal Rhodamine 6G “acceptor”. Furthermore, the 1,8-naphthalimide periphery of the system was designed on the “fluorophore-spacer-receptor” format, capable of acting as a molecular fluorescence photoinduced electron transfer based probe. Due to the both effects, photoinduced electron transfer in the periphery of the system and pH dependent rhodamine core absorption, novel antenna is able to act as a selective ratiometric pH fluorescence probe in aqueous medium. Thus, the distinguishing features of light-harvesting systems (fluorescence resonance energy transfer) were successfully combined with the properties of classical ring-opening sensor systems, which may be beneficial for monitoring pH variations in complex samples.

A highly selective ratiometric fluorescent pH probe based on a PAMAM wavelength-shifting bichromophoric system

A novel PAMAM wavelength-shifting bichromophoric system has been successfully developed. Novel compound was configured as a light harvesting antenna where the system surface is labeled with yellow–green emitting 4-(N,N-dimethylamino)ethylamino-1,8-naphthalimide “donor” units capable of absorbing light and efficiently transferring the energy to a focal Rhodamine 6G “acceptor”. The periphery of the system was designed on the “fluorophore–spacer–receptor” format, capable of acting as a molecular fluorescence photoinduced electron transfer based probe. Due to the both effects, photoinduced electron transfer in the periphery of the system and pH dependent rhodamine core absorption, novel antenna is able to act as a selective ratiometric pH fluorescence probe in aqueous medium. Thus, the distinguishing features of the fluorescence resonance energy transfer systems were successfully combined with the properties of classical ring-opening charge transfer systems, which may be beneficially for monitoring pH variations in complex samples.

Aza-crown-ether-appended xanthene: selective ratiometric fluorescent probe for silver(I) ion based on arene-metal ion interaction.

In this Communication, we report on the development of a ratiometric fluorescent probe for silver(I) ions (Ag(I)) based on an arene-metal ion interaction. The probe selectively senses Ag(I) among various metal ions with a large-emission red shift under aqueous conditions, enabling the selective ratiometric detection of Ag(I). X-ray crystallography and NMR analyses reveal that Ag(I) comes into close contact with the fluorophore, which induces a large-emission red shift. The high sensing selectivity of the probe toward Ag(I) might be attributable to the restricted rigid conformation of the cyclic aza crown ether, which exclusively binds Ag(I). In addition to Ag(I) sensing, the Ag(I) complex of the probe is also used for the ratiometric sensing of a cyanide anion (CN(-)), highlighting the utility of the reported probe in fluorescence sensing.

Alizarin Complexone as a highly selective ratiometric fluorescent probe for Al3+ detection in semi-aqueous solution

Abstract A simple and selective spectrofluorimetric method for the determination of trace levels of aluminum has been developed using Alizarin Complexone (AC). Exhibiting absorption and fluorescence changes in the presence of Al3+ in EtOH–H2O solution at pH 4.6, AC could be used as a colorimetric and fluorescent chemosensor for the detection of Al3+. In the presence of Al3+ ions, AC undergoes fluorescence quenching at 487 nm and shows the formation of a new red-shifted band at 558 nm. A good linear relationship could be obtained between the fluorescence intensity ratio (I487/I558) and the concentration of Al3+ ions in the range of 0.3–4.5 × 10−5 M (R2 = 0.9825). The intensity changes allow a ratiometric detection of Al3+ in acid semi-aqueous solution with the detection limit of 5.2 × 10−7 M. Moreover, the colorimetric and fluorescent response of AC to Al3+ can be conveniently detected by the naked eye, which provides a facile method for visual detection of Al3+. The optimized ground state geometry and corresponding UV–vis absorption spectral characteristics of AC and AC·Al3+ complex have also been calculated using Density Functional Theory (DFT) with CEP-31G basis sets.

A highly selective ratiometric fluorescent probe for in vitro monitoring and cellular imaging of human carboxylesterase 1

A new ratiometric fluorescent probe derived from 2-(2-hydroxy-3-methoxyphenyl) benzothiazole (HMBT) has been developed for selective monitoring of human carboxylesterase 1 (hCE1). The probe is designed by introducing benzoyl moiety to HMBT. The prepared latent spectroscopic probe 1 displays satisfying stability under physiological pH conditions with very low background signal. Both the reaction phynotyping and chemical inhibition assays demonstrated that hCE1 mediated the specific cleavage of the carboxylic ester bond of probe 1 in human biological samples. The release of HMBT leads to a remarkable red-shifted emission in fluorescence spectrum (120nm large emission shift). Furthermore, human cell-based assays show that probe 1 is cell membrane permeable, and it can be used for bioassay and cellular imaging of hCE1 activity in HepG2 cells. These findings lead to the development of a simple and sensitive fluorescent method for measurement of hCE1 activity in vitro or in living cells, in the presence of additional enzymes or endogenous compounds.

Selective ratiometric pH-sensing PAMAM light-harvesting dendrimer based on Rhodamine 6G and 1,8-naphthalimide

The paper reports on the divergent synthesis and fluorescence characteristics of a polyamidoamine (PAMAM) dendron of second generation. Novel compound is configured as a light harvesting antenna where the system surface is labeled with yellow-green emitting 4-(N-piperazinyl)-1,8-naphthalimide “donor” units capable of absorbing light and efficiently transferring the energy to a focal Rhodamine 6G “acceptor”. The energy transfer is calculated to 82%. Furthermore, the 1,8-naphthalimide periphery of the system is designed on the “fluorophore–spacer–receptor” format and is able to act as a molecular fluorescence photoinduced electron transfer based probe. Due to the both effects, photoinduced electron transfer in the periphery of the system and pH dependent rhodamine core absorption, novel antenna is able to act as a highly selective ratiometric pH fluorescence probe. Thus, the distinguishing features of light-harvesting systems (fluorescence resonance energy transfer) were successfully combined with the properties of classical ring-opening sensor systems.

A pH sensitive and selective ratiometric PAMAM wavelength-shifting bichromophoric system based on PET, FRET and ICT

A fluorescent poly(amidoamine)-based wavelength-shifting bichromophore was synthesized using divergent strategy and characterized photophysically. Novel compound was configured as a light-harvesting antenna where the systems surface is labelled with yellow-green emitting 4-(N-piperazinyl)-1,8-naphthalimide “donor” units capable of absorbing light and efficiently transferring the energy to a focal Rhodamine 6G “acceptor”. The energy transfer was calculated to 91%. Moreover, the 1,8-naphthalimide periphery of the system was designed on the “fluorophore–spacer–receptor” format able to act as a molecular fluorescence photoinduced electron transfer based probe. Due to the both effects, photoinduced electron transfer in the periphery and pH dependent spirolactam to ring-opening amide equilibrium of rhodamine core, novel bichromophoric system acts as a selective ratiometric pH fluorescence probe. Thus, the distinguishing features of light-harvesting (fluorescence resonance energy transfer) systems were successfully combined with the properties of classical photoinduced electron transfer and ring-opening sensing systems.

A highly selective ratiometric fluorescent probe for hydrogen peroxide displaying a large emission shift

A simple water-soluble 4-hydroxynaphthalimide-derived ratiometric fluorescent probe (1) containing a receptor of boronate moiety was designed and synthesized to detect hydrogen peroxide. Probe 1 could quantificationally detect hydrogen peroxide by ratiometric absorption and fluorescence spectroscopy methods with excellent selectivity and sensitivity. Interestingly, probe 1 exhibited 100nm red-shifted absorption spectra accompanying with the color changes from colorless to yellow-green, and 132nm red-shifted emission spectra upon addition of hydrogen peroxide. Thus, 1 can serve as a “naked-eye” probe for hydrogen peroxide. Additionally, the reaction mechanism of probe 1 and hydrogen peroxide was confirmed using 1H-NMR and ESI-MS. Bioimaging application further demonstrated that probe 1 would provide a promising method for the detection of hydrogen peroxide in living systems.

Highly selective ratiometric fluorescent probe for Au3+ and its application to bioimaging

The 4-propargylamino-1,8-naphthalimide based fluorescent probe 1 has been explored as a sensor for selective detection of Au3+. 4-Amino-1,8-naphthalimides, that possess typical intramolecular charge transfer (ICT) electronic characteristics, have been widely used as versatile platforms for fluorescent probes. The newly designed probe 1 contains a propargylamine moiety at C-4 of the naphthalimide chromophore that reacts with Au3+ to generate a product that has distinctly different electronic properties from 1. Specifically, the probe undergoes a remarkable change in its absorption spectrum upon addition of Au3+ that is associated with a distinct color change from yellow to light pink. In addition, a blue shift of ca. 56nm also takes place in the emission spectra of the probe. Consequently, 1 serves as a reaction-based sensor or so called chemodosimeter for Au3+. Importantly, surfactants enhance the rate of reaction of 1 with Au3+, thus, enhancing its use as a real time sensor. Finally, the results of studies probing its application to bioimaging of Au3+ in live cells show that the probe 1 has a unique ability to sense Au3+ in cells and, in particular, in lipid droplets within cells.