We report the specific collision of a single murine cytomegalovirus (MCMV) on a platinum ultramicroelectrode (UME, radius of 1 μm). Antibody directed against the viral surface protein glycoprotein B functionalized with glucose oxidase (GOx) allowed for specific detection of the virus in solution and a biological sample (urine). The oxidation of ferrocene methanol to ferrocenium methanol was carried out at the electrode surface, and the ferrocenium methanol acted as the cosubstrate to GOx to catalyze the oxidation of glucose to gluconolactone. In the presence of glucose, the incident collision of a GOx-covered virus onto the UME while ferrocene methanol was being oxidized produced stepwise increases in current as observed by amperometry. These current increases were observed due to the feedback loop of ferrocene methanol to the surface of the electrode after GOx reduces ferrocenium methanol back to ferrocene. Negative controls (i) without glucose, (ii) with an irrelevant virus (murine gammaherpesvirus 68), and (iii) without either virus do not display these current increases. Stepwise current decreases were observed for the prior two negative controls and no discrete events were observed for the latter. We further apply this method to the detection of MCMV in urine of infected mice. The method provides for a selective, rapid, and sensitive detection technique based on electrochemical collisions.collisions | cytomegalovirus | electrochemistry | electrovirology | ELISA T he development of methods to observe collisions on ultramicroelectrodes (UMEs) has allowed for the study of single entities, such as single nanoparticles (1), emulsion droplets (2, 3), vesicles (4, 5), biological macromolecules (6), and even single ions (7), in a digital manner (8). However, many of the techniques developed lack specificity. In the field of collisions, the study of biologically relevant analytes of interest, such as viruses and cells, has been largely unexplored. Perhaps the greatest challenges in these experiments are achieving specificity and understanding the electrochemical response. Overcoming these challenges will ultimately lead to the development of sensitive detection methodologies based on facile and inexpensive electrochemical methods, which will be of importance in the diagnosis of infectious diseases.Rapid, accurate diagnosis is a critical first step in the care of those suffering from viral infections. ELISAs, PCR-based techniques, or culture methods are fairly reliable diagnostic measures with varying degrees of sensitivity (9-11). However, these diagnostic techniques require a significant degree of sample and experimental preparation, increasing the amount of time between a positive diagnosis and the beginning of treatment. Diagnostic tools that are able to directly sample from complex media (i.e., blood, serum, urine, etc.) are necessary to expedite the diagnostic process.One such infectious agent that requires rapid and early detection is human cytomegalovirus (HCMV). HCMV is a prototypical betaherpesvirus, establ...

Fig. 4. Representative i-t curves for filtered toluene emulsion droplet systems for each oxidation of TTF1 and TTF2 at 0.5 and 1V , respectively,a nd the oxidation of TPrA and DPH. Each experiment was completed on an electrode with ad iameter of 1-3 mm.

<p>This review summarizes our own research, published since 2004, dealing with electrochemical reduction of halogenated organic compounds that are environmental pollutants. Included are sections surveying the direct and mediated reduction of the following species: (a) chlorofluorocarbons; (b) pesticides, fungicides, and bactericides; (c) flame retardants; and (d) disinfection by-products arising from the chlorination of water. To provide the reader with a perspective of these topics beyond our own work, a total of 238 literature citations, pertaining to studies conducted in numerous laboratories around the world, appears at the end of this review.</p>

Electrochemical reduction of primary (1‐halodecane), secondary (2‐halohexane and cyclohexyl halide), and tertiary halides (tert‐butyl halide) at a silver cathode in dimethylformamide (DMF) containing 0.050 M tetramethylammonium perchlorate (TMAP) was investigated with the aid of cyclic voltammetry and controlled‐potential (bulk) electrolysis for iodides, bromides, and chlorides. Selected reductions were probed in dried DMF–TMAP and DMF containing tetra‐n‐hexylammonium perchlorate (THAP). Cyclic voltammograms reveal that the number of cathodic peaks and their potentials are highly dependent on the identity and position of the halogen as well as the composition of the solvent–electrolyte. Intermediates arising from bulk electrolysis of these halides at silver undergo both radical and carbanion reactions. Electrolysis products depend on the identity and position of the halogen, amount of residual water, and size of the electrolyte cation in the solvent–electrolyte. Theoretical calculations of molecular dipole moments and polarizabilities were performed and compared to experimental observations.

No abstract