Anion chemosensors

Martmez-Manez R, Sancenon F (2005) New advances in fluorogenic anion chemosensors. JFluoresc 15 267-285... 

Kubo Y, Tsukahara M, Ishihara S et al (2000) A simple anion chemosensor based on a naphthalene-thiouronium dyad. Chem Commun 653-654... 

Sun S-S, Lees AJ. Transition metal based supramolecular systems synthesis, photophysics, photochemistry and their potential applications as luminescent anion chemosensors. Coord Chem Rev 2002 230 171-192. 

Metallocyclophanes with A-heterocyclic fragments as transition metal-based sup-ramolecular systems, their synthesis, photophysics, photochemistry, and potential applications as luminescent anion chemosensors 02CCR(230)170. 

Sun, S. S., Lees, A. J., Transition Metal Based Supramolecular Systems Synthesis, Photophysics, Photochemistry and their Potential Applications as Luminescent Anion Chemosensors, Coord Chem. Rev. 2002, 230, 171 192. 

Choi K, Hamilton AD (2001) A dual channel fluorescence chemosensor for anions involving intermolecular excited state proton transfer. Angew Chem Int Ed 40 3912-3913... 

Coskun A, Baytekin BT, Akkaya EU (2003) Novel fluorescent chemosensor for anions via modulation of oxidative PET a remarkable 25-fold enhancement of emission. Tetrahedron Lett 44 5649-5651... 

Fluorescent Chemosensors for Cations, Anions, and Neutral Analytes... 

A nitrate-selective potentiometric MIP chemosensor has been devised [197, 198]. For preparation of this chemosensor, a polypyrrole film was deposited by pyrrole electropolymerization on a glassy carbon electrode (GCE) in aqueous solution of the nitrate template. Potentiostatic conditions of electropolymerization used were optimized for enhanced affinity of the resulting MIP film towards this template. In effect, selectivity of the chemosensor towards nitrate was much higher than that to the interfering perchlorate ( o3 cio4 = 5.7 x 10-2) or iodide ( N03, r = x 10 2) anion. Moreover, with the use of this MIP chemosensor the selectivity of the nitrate detection has been improved, as compared to those of commercial ISEs, by four orders of magnitude at the linear concentration range of 50 pM to 0.5 M and LOD for nitrate of (20 10) pM [197]. 

Recently, Czamik et al. have reported the use of the acyclic protonated amine host 9 as a chemosensor of pyrophosphate. Typical fluorescence sensing methods rely on the ability of a complexed anion to quench the fluorophore. The fluorescence intensity of host 9, however, is actually increased upon complexation of anions and its 2200-fold selectivity of pyrophosphate over phosphate allows for real-time assay of pyrophosphate hydrolysis by inorganic pyrophosphatase.18... 

As far as chemical sensors are concerned, colorimetric chemosensors for anions based on calix[4]pyrrole (16-18, 22-31) showed strong binding to the fluoride anion. Receptors (29-31) are the first naked-eye detectable chemosensors that are able to discriminate between different anionic substrates as a result of detectable colour changes. On the other hand, the fluorescence of the receptors (16-18, 22-28) is quenched significantly in the presence of anionic guests. 

Metal ions play a quadruple role in fluorescent and chromogenic chemosensors they are the most common substrates some metal complexes are involved as receptors for anions and neutral molecules and some metal ions (of Ru, Re, Os, Eu, Tb) constitute fluorescent reporters. Furthermore, in some applications metal ions are structural elements of fluorescent chemosensors [7]. 

Lee HN, Singh NJ, Kim SK, et al. New imidazolium systems bearing two pyrene groups as fluorescent chemosensors for anions and anion induced logic gates. Tetrahedron Lett 2007 48 69-172. 

Rare Earth Complexes as Luminescent Chemosensors for Anions... 

Anions, such as fluoride, chloride, and phosphate, play critical roles in a range of biological processes and are implicated in a number of diseased states, ranging from fluorosis to cystic fibrosis [41]. Therefore, the exploitation of new luminescent chemosensors for anions is very important. The main design approach for lanthanide complexes as luminescent chemosensors for anions is to utilize the specific interaction between the anions and the lanthanide ion to realize the detection of the anions. 

Martinez-Manez, R. and Sancenon, F. (2003) Fluorogenic and chromogenic chemosensors and reagents for anions. Chemical Reviews, 103, 4419-4476. 

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