Direct detection of ion pairs by fluorescence enhancement

Silva, A. Prasanna de; McClean, Gareth D.; Pagliari, Sara

doi:10.1039/b305262a

Cited by 87 publications

(29 citation statements)

References 14 publications

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“…47). 92 This system, reported in 2003, contains both anion and cation binding sites, namely a Na + -selective benzo[15]crown-5 moiety and a H 2 PO 4 − -selective polyammonium group linked via an anthracene fluorophore. In the absence of substrates (ions), the fluorescence intensity of receptor 84 is inherently low because of PET (photo-induced electron transfer) from both the benzo[15]crown-5 and the benzylic amine lone pair to the anthracene.…”

Section: Ion Pair Receptors Based On Positively Charged Componentsmentioning

confidence: 99%

Ion pair receptors

2010

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Compared with simple ion receptors, which are able to bind either a cation or an anion, ion pair receptors bearing both a cation and an anion recognition site offer the promise of binding ion pairs or pairs of ions strongly as the result of direct or indirect cooperative interactions between co-bound ions. This critical review focuses on the recent progress in the design of ion pair receptors and summarizes the various binding modes that have been used to accommodate ion pairs (110 references).

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Section: Ion Pair Receptors Based On Positively Charged Componentsmentioning

confidence: 99%

Ion pair receptors

2010

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“…The PET-based "receptor 1 -spacer 1 -fluorophore-spacer 2 -receptor 2 " motif was also used in an AND logic gate working with ion pairs as chemical inputs. Incorporating a benzo-15-crown-5 ether to bind Na þ and a polyammonium site (developed by Czarnik [71]) to bind HPO 4 2À , 27 [72] showed increased fluorescence only when both species were present to freeze two PET channels that quenched fluorescence of the anthracene unit (one from the benzo-15-crown-5 ether and the other from the tertiary amine). The polyamine receptor in 27 had poor selectivity in the aqueous methanol solvent and could bind other anions such as Cl À , F À and BF 4 À prompting a fluorescence emission.…”

Section: Separate Inputsmentioning

confidence: 99%

Molecular Logic Gates and Luminescent Sensors Based on Photoinduced Electron Transfer

Silva

Uchiyama

2010

Luminescence Applied in Sensor Science

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The competition between Photoinduced electron transfer (PET) and other de-excitation pathways such as fluorescence and phosphorescence can be controlled within designed molecular structures. Depending on the particular design, the resulting optical output is thus a function of various inputs such as ion concentration and excitation light dose. Once digitized into binary code, these input-output patterns can be interpreted according to Boolean logic. The single-input logic types of YES and NOT cover simple sensors and the double- (or higher-) input logic types represent other gates such as AND and OR. The logic-based arithmetic processors such as half-adders and half-subtractors are also featured. Naturally, a principal application of the more complex gates is in multi-sensing contexts.

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“…Among the PET chemosensors there are also ditopic systems such as compounds 53 [72] and 54 [73], capable of detecting sodium phosphate and potassium fluoride respectively. More rarely, the so-called CHEQ (chelation enhanced fluorescence quenching) PET sensors, in which fluorescence quenching is observed during the formation of their complexes with metal ions, have been used for analytical purposes.…”

Section: Fluorescent Chemosensorsmentioning

confidence: 99%

Organic chemosensors with crown-ether groups (review)

Цуканов

Дубоносов

Breń

et al. 2008

Chem Heterocycl Comp

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Recent advances in the chemistry of organic chemosensors containing crown-ether groups are reviewed.Organic chemosensors are molecules of abiotic nature capable of interacting selectively and irreversibly with a specific substrate (ion, molecule) with corresponding changes in one or more characteristics of the system. A series of reviews have described methods for the synthesis of chemosensors [1] and their use in the determination of metal cations [2-8], anions, and molecules [4, 9, 10]. Some of them treat the various types of fluorescent chemosensors [5][6][7][8] or photoswitching compounds [11][12][13][14] selectively. In this review, based exclusively on the results of recent years, sensors containing crown-ether groups are examined. Special attention is paid to the various mechanisms of action of crown-containing chemosensors, which are classified according to their electronic and photochemical characteristics.In the general case a chemosensor molecule consists of signal and receptor parts with a bridge between them although the latter may be absent. As a rule chemosensors can be subdivided into chromogenic, fluorescent, and photoswitchable.During the interaction of a chromogenic sensor with the substrate (in particular with a metal ion) a hypsochromic or bathochromic shift of the long-wave absorption band of the initial compound is observed. If the shift of the bands is significant and takes place in the visible part of the spectrum it leads to a visually discernable change in the color of the solution. Such signal systems are usually called colorimetric or "naked-eye" chemosensors.The action of fluorescent chemosensors is based both on change of the fluorescence intensity and on shift of the emission band of the initial compounds during the formation of a complex with the substrate.Photoswitchable chemosensors are capable of reversible "switching on-switching off" of their sensor characteristics under the influence of light.Among ionophore-receptors capable of combining with positively charged ions, it is possible to include chelating agents, podands, coronands (or crown ethers), cryptands, calixarenes, cyclodextrins, etc. [15].Crown ethers, discovered by Pedersen in 1962, occupy a special position among receptors and are widely used in the design of new chemosensors based on their unique ability to combine with the cations of alkali metals, their fairly high selectivity, and their accessibility. In addition to alkali metals, crown ethers are also effective complexing reagents for the cations of alkaline-earth metal, Pb 2+ , and Tl 2+ , and when nitrogen and sulfur atoms are inserted into their structure they become sensitive to Ag + , Hg 2+ , and Cd 2+ ions. The __________________________________________________________________________________________

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Direct detection of ion pairs by fluorescence enhancement

Abstract: Sensor 1 signals the simultaneous presence of sodium and phosphate with an increased fluorescence signal in the manner of a photoionic AND logic gate.

Cited by 87 publications

References 14 publications

Ion pair receptors

Ion pair receptors

Molecular Logic Gates and Luminescent Sensors Based on Photoinduced Electron Transfer

Organic chemosensors with crown-ether groups (review)

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