We demonstrate a new method of achieving rectification in single molecule devices using the high-bias properties of gold-carbon bonds. Our design for molecular rectifiers uses a symmetric, conjugated molecular backbone with a single methylsulfide group linking one end to a gold electrode and a covalent gold-carbon bond at the other end. The gold-carbon bond results in a hybrid gold-molecule "ga...

A novel nonseparation electrochemical enzyme immunoassay (NEEIA) for detecting marker proteins in undiluted blood is described. The approach is based on preferential electrochemical measurement of surface-bound enzyme-labeled reporter antibody (E-Ab), relative to an excess of this reagent in the sample solution. NEEIAs are carried out on microporous membranes coated with a thin, circular area o...

Formation of self-assembled monolayers (SAMs) of thioctic acid (TA) on polycrystalline gold electrodes has been investigated. The Au electrodes are polished, first mechanically and subsequently electrochemically, until the roughness of the surface is minimal. The best TA SAMs are formed onto these electropolished electrodes from stirred solutions, while a potential E = 0.0 V or E = +0.2 V versu...

Implantable microelectrodes have the potential to become part of neural prostheses to restore lost nerve function after nerve damage. The initial adsorption of proteins to materials for implantable microelectrodes is an important factor in determining the longevity and stability of the implant. Once an implant is in the body, protein adsorption takes place almost instantly before the cells reac...

A highly conducting electronic contact between a strained disilane and Au is demonstrated through scanning tunneling microscope-based single-molecule measurements. Conformationally locked cis diastereomers of bis(sulfide)-anchor-equipped 1,2-disilaacenaphthenes readily form high-conducting junctions in which the two sulfide anchors bind in a bipodal fashion to one gold electrode, providing enou...

An amperometric cytochrome c-based electrode was developed and applied to the quantification of the scavenging capacity of antioxidants. The enzymatic biosensor was constructed by covalently immobilizing both cyt c and XOD on a mercaptoundecanoic acid/mercaptoundecanol mixed SAMmodified screen-printed gold electrode. The concentration which induces a 50% inhibition of the superoxide level (IC50...

A straightforward flow injection method for the tensammetric determination of surfactants is described. The flow-through cell is equipped with a mercury-coated gold electrode as the working electrode. Ionic as well as nonionic surfactants can be determined in the concentration range 10~5-104 M. The calibration graph is not linear but with an approximation by a polynomial or a cubic spline funct...

It is proposed that direct electron transfer is dependent on the orientation of the heme plane in cytochrome c (cyt c) assembled on electrode surfaces. Orientation with the heme plane in cyt c parallel to the gold electrode surface favors the direct electron transfer, while vertical orientation of the heme plane makes the direct electron transfer difficult. A preferable electron transport pathw...

A micro glucose sensor consisting of an interdigitated array gold microelectrode was developed. The interdigitated array structure, which has 10 microns band width and 10 microns band gap, was fabricated in a small region (2.5 x 5 mm2) on a quartz substrate. Glucose oxidase was chemically fixed onto the electrode surface through self-assembled monolayer of 11-mercaptoundecanoic acid; ferrocenea...

The recording of electrophysiological activities of brain neurons in the last half-century has been considered as one of the effective tools for the development of neuroscience. One of the techniques for recording the activity of nerve cells is the multi-electrode arrays (MEAs). Microelectrode arrays (MEAs) are usually employed to record electrical signals from electrogenic cells like neurons o...