Molecularly Imprinted Polymers.

Molecularly imprinted polymers are synthetic receptors for a targeted molecule. As such, they are analogues of the natural antibody-antigen systems. In this review, after a recounting of the early history of the general field, we specifically focus on the application of these polymers as sensors.

Thermochemical study of amino acid imprinted polymer films.

Molecularly imprinted polymers provide an alternative to traditional methods of amino acid analysis. The imprinted polymers are more robust and significantly less expensive than, for example, ELISA analysis. Amino acid imprinted nylon-6 thin films were studied by differential scanning calorimetry and scanning electron microscopy.

Properties of transition metal substituted zinc sulfide hexamers and dodecamers.

Density functional theory was used to study the structural and electronic properties of endohedrally- and substitutionally-doped Zn6S6 and Zn12S12 clusters with first-row transition metal atoms. Generally, the lowest energy electronic state of the cluster is that with the maximum multiplicity (Ti and Cr are exceptions). Substitutionally-doped clusters have greater binding energies (per atom) for both cluster sizes, providing an indication that similar doping will be preferred in the bulk material as well.

A selective molecularly imprinted polymer-carbon nanotube sensor for cotinine sensing.

Conductive composite films comprised of single-walled carbon nanotubes coated with molecularly imprinted poly-4-vinylphenol are produced and characterized using ultraviolet and infrared spectroscopies, confirming the successful molecular imprinting of the film with cotinine. The electrical resistance of the imprinted film changes significantly upon binding cotinine, by more than 30 kΩ, while the unimprinted film in comparison elicits little response. Additionally, once the cotinine template desorbs from the film, the resistance of the imprinted film returns to a value close to the pre-adsorption baseline.

Nanomaterials in Sensors.

This Special Issue of is focused on the continuing implementation of nanomaterials and nanostructures in the development of more sensitive and more specific sensing devices. As a result, these new devices employ smaller sensing elements and provide more "real time" capability. Often, the inclusion of nanomaterials leads to sensing elements for targets that were previously inaccessible.

Detection of secondhand cigarette smoke via nicotine using conductive polymer films.

Introduction: The 2006 U.S. Surgeon General's Report found that there is no safe level of exposure to secondhand smoke (SHS).

Impact of surface steps and oxygen pre-coverage on the adsorption of methylamine on gold.

Using density functional theory calculations, we report on the adsorption of methylamine on gold and compare its adsorption to a selection of alkylamines, methanol and methanethiol. On the (111) surface, the amines, thiol and alcohol bind in the ontop site with a preference over hollow and bridge sites of 0.3 eV, 0.

Small germanium sulfide clusters: mass spectrometry and density functional calculations.

Germanium sulfide clusters were generated by laser ablation of a solid sample. The resulting molecules were analyzed in a time-of-flight mass spectrometer. In addition to atomic germanium and diatomic sulfur, the spectra exhibited evidence for the existence of clusters containing up to four germanium atoms.

Studies of neutral and ionic CuAr and CuKr van der Waals complexes.

Ab initio calculations of the interaction potential between Cu (or Cu(+)) and Ar (or Kr) have been carried out. A range of theoretical methods, including Hartree-Fock (HF), Moeller-Plesset perturbation methods to second order (MP2), and single and double excitation coupled cluster methods, with the perturbational effect of triple excitations (CCSD(T)), were employed with relativistic pseudopotential basis sets. The effects of bond functions and diffuse polarization (f, g, h) functions were tested on the calculation of the weak intermolecular interactions.

Experimental and computational study of the Zn(n)S(n) and Zn(n)S(n)+ clusters.

Zinc sulfide clusters produced by direct laser ablation and analyzed in a time-of-flight mass-spectrometer, showed evidence that clusters composed of 3, 6, and 13 monomer units were ultrastable. The geometry and energies of neutral and positively charged Zn(n)S(n) clusters, up to n = 16, were obtained computationally at the B3LYP/6-311+G level of theory with the assistance of an algorithm to generate all possible structures having predefined constraints. Small neutral and positive clusters were found to have planar geometries, neutral three-dimensional clusters have the geometry of closed-cage polyhedra, and cationic three-dimensional clusters have structures with a pair of two-coordinated atoms.

Small, nonstoichiometric zinc sulfide clusters.

Recent experiments indicated that the formation of small, nonstoichiometric clusters Zn(n)S(m) and Zn(n)S(m)+ was possible. In this work, the ground states of these clusters, where 1 < or = n, m < or = 4, were studied using density functional theory. Global minima were found to be primarily cyclic structures in which the S-Zn-S preference for large bond angles was preserved.

Density functional theory study of the Jahn-Teller effect and spin-orbit coupling for copper and gold trimers.

The Born-Oppenheimer potential energy hypersurfaces of copper and gold trimers were calculated using density functional theory with an analytic potential. The calculated Jahn-Teller distortion energies, pseudorotation barriers, dissociation, and isomerization energies for the two trimers are discussed. Global minima from the surfaces were optimized using the density functional theory method as well as the coupled cluster-singles-doubles-with-triples energies technique.

Experimental and computational study of small (N = 1-16) stoichiometric zinc and cadmium chalcogenide clusters.

Zinc selenide, cadmium sulfide, and cadmium selenide clusters were produced by direct laser ablation and analyzed in a time-of-flight mass spectrometer. The positive-ion mass spectra indicated that clusters composed of six and thirteen monomer units were ultrastable in all cases. The geometries and energies of the neutral and positively charged M(n)X(n) clusters up to n = 16 were obtained computationally at the B3LYP level of theory using the SKBJ basis set for the metal atoms and the SKBJ(d,2df) basis set for the chalcogen atoms.