Mercury-gold minigrid optically transparent thin-layer electrode

Abstract

relates to the directed dipole of a molecule which one could argue would determine the size and shape of the puncture a molecule made in the dipolar membrane of a neuron. Possibly one could even eliminate the necessity of full penetration of the molecule into the interior of the neuron, and hypothesize that the presence of the molecule on the surface and the consequent disordering of the membrane would be sufficient. The second axis correlates to the first u electron excitation energy, which one would expect to correlate to Lewis acidity. Whichever one is chosen, it could possibly be sensed by the effect of the molecule on some biochemical pathway which involved electron transfer. ACKNOWLEDGMENTThe authors thank Dave Kalman, who helped us decipher the CNDO data, Carl Appellof and Jim Koskinen for writing the 3-dimensional model building program, and M. da Koven for moral support. LITERATURE CITEDAn optlcaliy transparent thin-layer electrode (OTTLE) with characterlstics of mercury has been prepared by electrodepositing a thin film of mercury on a 500-lpi gold minigrid. The negative potential range of this Hg-Au OTTLE was 500 mV greater than that obtained on a Au OTTLE and 200 mV greater than that reported for a Hg-NI OllLE. The large hydrogen overvoltage is attributed to the good overvoltage characteristics of the gold substrate, which is quite soluble in mercury, and to the formation of a continuous mercury film rather than droplets. The optical transparency of the gold minigrid (60%) was not measurably diminished by deposition of the mercury film. The extended negative potential range Is useful for observing electrode processes with large negative reduction potentials as illustrated by vitamin BI2 and glyoxyllc acld.

A surface-modified gold minigrid electrode which heterogeneously reduces spinach ferredoxin

“…Surface analysis of these electrodes using ESCA and Auger spectroscopy is planned. 22 It is proposed that the product of the chemical reaction which coats the electrode is a polymer of MV. The recent work of Simon and Moore1* describes the chemical preparation of a series of polyviologens for use as photochromic redox polymers with film-forming properties.…”

Spectroelectrochemical determination of the redox potential of pheophytina, the primary electron acceptor in photosystem II

“…An airtight OTTLE cell, being an adapted version of the basic design reported by Hawkridge and Ke (24), was used for the spectroelectrochemical measurements. The optical path length was Ϸ300 m, and the effective cell volume was 500 L. A gold minigrid (100 mesh per inch) electrode, rinsed by ultrasonification in dilute HNO3 and then in ultrapure water, was electroplated cathodically with mercury by applying a potential of approximately Ϫ1.0 V in a solution of saturated Hg(NO3)2 by using a potentiostat until the entire electrode surface turned to shiny gray (59). The Hg-Au mesh served as a working electrode, a Pt black wire as a counter electrode, and an Ag-AgCl (in saturated KCl) as a reference electrode in the thin-layer cell.…”

Spectrophotometric investigation of products formed following the initial one-electron electrochemical reduction of nicotinamide adenine dinucleotide (NAD+)

“…The working electrode was a 500 lines per inch gold wire mesh (Buckbee Mears Co., St. Paul, MN). After assembly, it was amalgamated according to the method of Meyer et al [19]; pretreatment in the plasma cleaner was not necessary. The active mesh area was 10 mm high by 9 mm wide.…”