This critical review describes a class of polymers prepared by electrochemical polymerization that employs the concept of molecular imprinting for chemical sensing. The principal focus is on both conducting and nonconducting polymers prepared by electropolymerization of electroactive functional monomers, such as pristine and derivatized pyrrole, aminophenylboronic acid, thiophene, porphyrin, aniline, phenylenediamine, phenol, and thiophenol. A critical evaluation of the literature on electrosynthesized molecularly imprinted polymers (MIPs) applied as recognition elements of chemical sensors is presented. The aim of this review is to highlight recent achievements in analytical applications of these MIPs, including present strategies of determination of different analytes as well as identification and solutions for problems encountered.

Republication or reproduction of this report or its storage and/or dissemination by electronic means isAbstract: Theory, preparation, and applications of microelectrodes and microelectrode arrays are critically reviewed, and future trends in the field are outlined. An operational definition of a microelectrode is also recommended.

The electroreductions of Buckminsterfullerene (c60) in aprotic solvents were examined as a function of solvent, supporting electrolyte, and temperature. Altogether, 11 different solvents and 17 different supporting electrolytes were utilized in measurements made between 223 and 348 K. The cations of the supporting electrolytes were Li' and Na+ as well as quaternary ammonium and quaternary phosphonium cations. The anions of the supporting electrolytes were C104-, BF4-, PF6-, and Br-. Cyclic voltammograms, rotating disk electrode voltammograms, and controlled potential coulometry revealed up to five reversible one-electron reductions. A qualitative approach is used to elucidate the effects of solvent, supporting electrolyte, and temperature on the half-wave potentials, E l / z , of the reductions of c 6 0 . E l l 2 for the first reduction correlates well with the Gutmann donor number of the solvent with a positive slope, but it also shows a linear correlation with the Gutmann acceptor number of the solvent with a negatiue slope. In contrast, the third reduction E1/2 correlates fairly with the Gutmann acceptor number with a positive slope. The first three reductions also correlate with the normalized Dimroth-Reichardt solvent parameter. The inorganic anions of the supporting electrolytes do not significantly affect the half-wave potentials, but these values vary substantially with the type and size of the supporting electrolyte cations. The relative magnitudes of the solvent and supporting electrolyte effects on E l I z differ for each redox process of Cdo, and values of shift over a range of 280-600 mV for a given redox couple. The shifts in reduction potentials were rationalized in terms of the following: (i) charge density on the fulleride anions, (ii) solvophobic effects involving Cso (aggregation), (iii) solvophobic type interactions involving Cm anions and the larger cations of the supporting electrolytes in polar solvents, (iv) ion pairing of Cdo anions with smaller cations in nonpolar solvents, and (v) the specific acceptor or donor properties of the solvents. The reversible half-wave potentials were also measured as a function of temperature in eight different solvent/supporting electrolyte systems, and the measured values of AElI2/AT were used to calculate the change of entropy associated with each electron-transfer step. The shifts in E l I z with temperature are relatively large and indicate that an unusually large change of entropy accompanies each electroreduction step. Diffusion coefficients, Stokes radii, and apparent solvation numbers of neutral Cdo were also determined in different solvent systems, and these values are discussed with respect to the nature of the solventsolute interaction.

The electrochemical behavior of fullerene and fullerene derivatives are reviewed with special reference to their catalytic and sensor applications. Recent work on carbon nanotubes, used as catalyst supports in heterogeneous catalysis and sensor development is also presented. An overview of recent progress in the area of fullerene electrochemistry is included. Several cases of electrocatalytic dehalogenation of alkyl halides, assisted by the electrode charge transfer to fullerenes, are discussed. Research work on the electrocatalysis of biomolecules, such as hemin, cytochrome c, DNA, coenzymes, glucose, ascorbic acid, dopamine, etc. have also been considered. Based on the studies of the interaction of fullerenes, fullerene derivatives, and carbon nanotubes with other molecules and biomolecules in particular, the possibilities for the preparation of electrochemical sensors and their application in electroanalytical chemistry are highlighted.

The typical design of chiral electroactive materials involves attaching chiral pendants to an electroactive polyconjugated backbone and generally results in modest chirality manifestations. Discussed herein are electroactive chiral poly-heterocycles, where chirality is not external to the electroactive backbone but inherent to it, and results from a torsion generated by the periodic presence of atropisomeric, conjugatively active biheteroaromatic scaffolds, (3,3'-bithianaphthene). As the stereogenic element coincides with the electroactive one, films of impressive chiroptical activity and outstanding enantiodiscrimination properties are obtained. Moreover, chirality manifestations can be finely and reversibly tuned by the electric potential, as progressive injection of holes forces the two thianaphthene rings to co-planarize to favor delocalization. Such deformations, revealed by CD spectroelectrochemistry, are elastic and reversible, thus suggesting a breathing system.

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