Sensors for neutral molecules

Details Sensors for neutral molecules Sensors for neutral molecules

1996-04-23

1998-06-23

Soderquist, Arlen

Chemistry: analytical and immunological testing

Measurement of electrical or magnetic property or thermal...

204415, 422 8201, 422 8202, 422 8203, 436103, 436104, 436150, 436151, 436183, 524108, G01N 27333, G01N 3300, C08K 515

Patent

active

057704538

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to the use of calixarenes in sensing chemical agents, particularly neutral charge agents, and to calixarene containing conductive materials sensitive to these agents. Further provided are electrodes incorporating these conductive materials, sensor devices incorporating such calixarene based electrodes and novel calixarenes suitable for use in such electrodes and devices.
A number of organic compounds have been demonstrated to have the ability to interact with neutral molecules in a host guest fashion whereby the neutral molecule is included within voids in the host compound. Examples of these interactions include those between cyclophanes and aromatics such as naphthalene, xylene and durene; between cryptophanes and chlorocarbons; and between cavitands and guests such as acetonitrile, chloroform and aromatics. These interactions have application in a variety of fields whereby a guest can be either applied in a solvent it is otherwise not soluble in, or in the removal or collection of the host from an environment where it in not desired or where it is to be recovered for use.
A further important group of host molecules are the calixarenes, a group of ring compounds comprising phenol formaldehyde condensation products, commonly having 4, 5, 6 or 8 phenolic monomers linked to each other at their 2, 5 positions; these particular molecules being referred to as respectively. Study of complex formation of calixarenes with neutral molecules in chloroform utilising aromatic solvent-induced shift (ASIS) NMR has demonstrated a weak interaction between the tetrameric calixarenes have failed to demonstrate complexation with numerous other guests, thought to be because of host solvent interaction (Gutsche and Bauer; Tet. Lett. (1981) 22 4763 and J.Am.Chem.Soc. (1985), 6052). The effects of dimethyl sulphide (DMS) on the cyclic voltammogram (CV) of Martin in his PhD thesis (October 1991-University of Birmingham, UK `The synthesis and evaluation or calixarene hydrophobic hosts designed to recognise small organic molecules`). Upon addition of one equivalent or DMS current peak potentials were found to be shifted by 80 mV and -20 mV for oxidation and reduction respectively. Peak currents for both oxidation and reduction diminished by 15 to 20% simultaneously. This phenomenon was explained as being related to DMS inclusion at the `upper rim` of the calixarene where para-substituents were present, whereby the substituents were pushed apart leading to conformational changes at the `lower rim` giving rise to changes in the electronic environment. In this case the lower rim was substituted with a redox active substituent.
Although inclusion of the structurally similar DMSO has been demonstrated by crystal X-ray analysis, the inclusion of DMS as reported by Martin has proven difficult to reproduce. The failure to realise this effect has led the present inventors to reconsider the strategy of use of redox active calixarenes in sensing of neutral compounds, as they have determined that the distance between the `upper rim` and `lower rim` groups is too great for there to be a significant and reliable influence of lost guest interaction on the redox properties of the lower rim. They have instead provided a novel approach whereby they substitute calixarenes at the `upper rim` with redox active groups and find that this gives reliable reporting of the presence of guest host interaction.
The present inventors have further found that the polymerisation of these calixarenes onto the surface of a conductive substrate does not produce a conductive effect whereby the upper rim conformational changes can be detected through that substrate. However, they have determined that if a copolymer of an organic conductive monomer and the calixarenes is so produced, these guest host conformational changes can be detected in this manner. Thus they have determined a method by which calixarene coated electrodes may be provided that can report back the presence of guest agents, particularly neutral molecules but also charged o

REFERENCES:
patent: 5132345 (1992-07-01), Harris et al.
patent: 5216185 (1993-06-01), Harris et al.
P.D. Beer et al. J. Organomet. Chem. 1988, 353, C10-C12.
P.D. Beer et al. J. Organomet. Chem. 1989, 378, 437-447.
A.M. Cadogan et al. Analyst 1989, 114, 1551-1554.
P.D. Beer et al. J. Chem. Soc., Dalton Trans. 1990, 3675-3682.
P.D. Beer et al. J. Organomet. Chem. 1991, 421, 265-273.
A.R. van Doorn et al. J. Org. Chem, 1991, 56, 2371-2380.
F. Porteu et al. J. Phys. Chem. 1991, 95, 7438-7447.
A. Cadogan et al. Anal. Chem. 1992, 64, 2496-2501.
P.D. Beer et al. Tetrahedron 1992, 48, 9917-9928.
P.D. Beer et al. J. Chem. Soc. Chem. Commun. 1993, 229-231.
P.R. Teasdale et al. Analyst 1993, 118, 329-334.
P.D. Beer et al. J. Chem. Soc. Chem. Commun. 1993, 828-830.
Atwood et al Inorg. Chem. 1992, 31, 603-606 "Metal Ion Complexes of
Chemical Abstracts, vol. 118 (15), No. 146978b see compound RN146469-56-9.
Chemical Abstracts, vol. 117(21), No. 212471P see compounds RN 144151-17-7 and 117750-21-7.
Chemical Abstracts, vol. 107 (15), No. 134021u see compound RN 108817-14-7.

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