Chemical sensors amines

The first report of surface-immobilized dendrimers was in 1994 [54]. Subsequently, our research group showed that the amine-terminated PAMAM and PPl dendrimers could be attached to an activated mercaptoimdecanoic acid (MUA) self-assembled monolayer (SAM) via covalent amide linkages [55, 56]. Others developed alternative surface immobilization strategies involving metal com-plexation [10] and electrostatic binding [57]. These surface-confined dendrimer monolayers and multilayers have found use as chemical sensors, stationary phases in chromatography, and catalytic interfaces [41,56,58,59]. Additional applications for surface-confined dendrimers are inevitable, and are dependent only on the synthesis of new materials and the development of clever, new immobilization strategies. 

Molecular design and rational synthesis of inorganic microporous crystalline materials are frontier subjects in the fields of zeolites science and molecular engineering. Zeolite synthesis is an active field of research because zeolites with uniform micropores are important in many industrial processes in catalysis, adsorption, and separation, and are finding new applications in electronics, magnetism, chemical sensors, and medicine, etc.12 91 Synthesis of such materials typically involves crystallization from a gel medium under hydrothermal/solvothermal conditions in the presence of organic amines as... 

Composites of PANI-NFs, synthesized using a rapid mixing method, with amines have recently been presented as novel materials for phosgene detection [472]. Chemiresistor sensors with nanofibrous PANI films as a sensitive layer, prepared by chemical oxidative polymerization of aniline on Si substrates, which were surface-modified by amino-silane self-assembled monolayers, showed sensitivity to very low concentration (0.5 ppm) of ammonia gas [297]. Ultrafast sensor responses to ammonia gas of the dispersed PANI-CSA nanorods [303] and patterned PANI nanobowl monolayers containing Au nanoparticles [473] have recently been demonstrated. The gas response of the PANI-NTs to a series of chemical vapors such as ammonia, hydrazine, and triethylamine was studied [319,323]. The results indicated that the PANI-NTs show superior performance as chemical sensors. Electrospun isolated PANI-CSA nanofiber sensors of various aliphatic alcohol vapors have been proven to be comparable to or faster than those prepared from PANI-NF mats [474]. An electrochemical method for the detection of ultratrace amount of 2,4,6-trinitrotoluene with synthetic copolypeptide-doped PANI-NFs has recently been reported [475]. PANI-NFs, prepared through the in situ oxidative polymerization method, were used for the detection of aromatic organic compounds [476]. 

Dermody, D.L., et al.. Chemically grafted polymeric filters for chemical sensors hyperbranched poly(acrylic acid) films incorporating beta-cyclodextrin receptors and amine-functionalized filter layers. Langmuir, 1999. 15(3) p. 885-890. Laschewsky, A., et al.. Polyelectrolyte multilayers containing photoreactive groups. Macromol Chem Phys, 1997. 198(10) p. 3239-3253. 

Mohr G. Citterio D., Demuth C., Fehlmann M., Luzi J., Lohse C., Moradian A., Nezel T., Rothmaier M. Spichiger U.E., Reversible chemical reactions as the basis for optical sensors used to detect amines, alcohols and humidity, Journal of Materials Chemistry 1999 9 2259. 

In general, EC reactions are typically observed according to the following general rank order (by relative ease of oxidation) o,p-quinol and o,p-aminophenol > tertiary amine > m-quinol rv phenol rv arylamine > secondary amine thiol > thioether primary amines, aliphatic alcohols. (HDVs) each redox active metabolite are obtained from the response across adjacent EC-Array sensors. These data are a reflection of the kinetic and thermodynamic components of electron transfer reactions. Since chemical structure is a critical determinant of an analyte s redox behavior, the intrinsic generation of an HDV with EC-Array provides qualitative information for each species. 

James TD, Samankumara KRAS, Shinkai S. Novel photoinduced electron-transfer sensor for saccharides based on the interaction of boronic acid and amine. Chemical Communications 1994, 4, 477 178. 

Fig. 7 Multispot sensor arrays composed of nanoporous pigment microspheres, exhibiting different responses to aliphatic amines. By combination of different pigment particles, fingerprint patterns specific for each amine can be obtained. Reprinted, with permission, from [78]. Copyright (2008) American Chemical Society...

One constant problem for crown ether based sensors in vivo is the ubiquitous presence of chemical species that will compete with the target analyte for the sensor binding site. For sensors incorporating [18]crown-6 this especially problematic as sodium, potassium, ammonium and hydronium (H30+) cations are all attracted to the threefold symmetry of the crown s cavity. Protonated terminal amines, including amino acids and peptides, can also interfere with analyte detection. It is therefore all the more pleasing when a crown ether based sensor is developed that does not bind to biologically common cations. This is the case for a saxitoxin chemosensor reported by Gawley, LeBlanc and co-workers [24],... 

The previous parts of Sect. 5 testify to the fact that development of sensors for a given chemical species is dependent on the availability of receptors with suitable selectivity, electroactivity and optical transparency. These criteria were most easily satisfied with amine derivatives with various structural modifications for the binding of protons, alkali and alkaline earth cations. Such is the ubiquity of the amine motif in fluorescent PET research that several of the examples to be discussed in this section also contain it within their receptors. 

The result will often be the eutrophication of lakes and coastal waters [238]. The area of phosphate sensors, including both chemical and biosensors, has been reviewed in 1998 by Engblom [239]. Phosphate biosensors have been reviewed by Amine and Palleschi [240]. 

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