Electrodes ultrasmall

Gichuhi etal. [439] have used Au(lll) electrode covered with the initial under-potentially deposited Cd layer. When H2S was electrolyzed at this surface, applying underpotential, an adlattice of the S—S interatomic spacing equal to 0.34 nm was obtained. The second monolayer of Cd and S had the same structure as the first CdS monolayer, showing that these two CdS monolayers were epitaxial. However, the third deposited monolayer of CdS exhibited interatomic spacing as observed for the bulk CdS. A direct fabrication of monodispersed, ultrasmall nanocrystals from the SAMs at Au(lll) substrate has also been described [440]. Reconstruction of CdS monolayers has been studied by Demir and Shannon [441]. 

In practical molecular devices, the supramolecular system is sometimes immobihzed on an external devices which reads the output from the system. An electrode is a typical example of this kind of external device. Various electrodes with ultrasmall dimensions are available, and are therefore well-suited to molecular device preparation. Electrodes can also be used as a soHd support for LB films and self-assembled monolayers. In the example shown... 

Challenge Problem. A new method for determining ultrasmall (nL) volumes by anodic stripping voltammetry has been proposed (W. R. Vandaveer and I. Fritsch, Anal. Chem., 2002, 74, 3575). In this method, a metal is exhaustively deposited from the small volume to be measured onto an electrode, from which it is later stripped. The solution volume 1/ is related to the total charge Q required to strip the metal by... 

The term nanode has been introduced to describe electrodes with at least one dimension in the nanometer size range [8], Although their fabrication and characterization remain challenging, these ultrasmall probes with critical dimensions approaching those of individual molecules are now an integral part of the field. 

Ultramicroelectrodes Ultrasmall electrodes of characteristic dimensions less than 1 /im are increasingly used in diverse research areas such as... 

Li, Z.-Y, Zhou, W, Wu, Z.-X. et al. 2009. Fabrication of size-controUable ultrasmall-disk electrode Monitoring single vesicle release kinetics at tiny structures with high spatio-temporal resolution. Biosens. Bioelectron. 24 1358—1364. 

Shim J-J (2015) Ultrasmall Sn02 nanoparticle-intercalated graphene polyaniline composites as an active electrode material for supeieapacitors in different electrolytes. Synth Met 207 110-115... 

INTRACELLULAR VOLTAMMETRY WITH ULTRASMALL CARBON RING ELECTRODES... 

There has been intense interest recently in the development of ultrasmall electrodes for voltammetry - . However, very few of these electrodes have small structural supports in addition to small electroactive area. We have used carbon deposition by hydrocarbon pyrolysis to fabricate ultrasmall ring-shaped carbon electrodes . Although hydrocarbon pyrolysis has been used to construct carbon electrodes , the novel aspect of our work is the fabrication of structurally ultrasmall electrodes. 

Carbon ring electrodes with structurally ultrasmall tip diameters were fabricated as described elsewhere. Electrodes with 3-5 pm tip diameters were used for intracellular voltammetry. Electrodes used for characterization ranged from 3 to 15 im in tip diameter. 

Voltammetry of dopamine at a 4 pm tip diameter carbon ring electrode is shown in Figure 3. A key feature of this electrode is the useful dynamic range for dopamine concentration measurement (micromolar to milli-molar). Additionally, sigmoidal shaped voltammograms are observed at moderate scan rates as expected for ultrasmall electrodes . 

Intracellular Voltammetry with Ultrasmall Carbon Ring Electrodes... 

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