We have bridged a pair of gold electrodes with various arrangements of gold nanoparticles stabilized with citrate molecules. The resulting devices exhibited current fluctuations at a constant bias voltage and fluctuations of the differential conductance as a function of the bias voltage. These fluctuations were attributed to the interplay of molecular conformation, charge switching, and breakin...

Cadmium(II) is a common water pollutant with high toxicity. It is of significant importance for detecting aqueous contaminants accurately, as these contaminants are harmful to human health and environment. This paper describes the fabrication, characterization, and application of an environment-friendly graphene (Gr)/L-cysteine/gold electrode to detect trace levels of cadmium (Cd) by differenti...

0a thin film of cobalt hexacyanoferrate (cohcf), an analogue of mixed-valence prussian blue, was deposited electrochemically on the glassy carbon, platinum and gold electrode surfaces in 0.5m kc1 solution. the electrochemical behavior of these modified electrodes show three couples of redox peaks by cv in a supporting electrolyte solution of 0.5m nacl, whereas for au modified electrode only one...

A label-free aptasensor for platelet-derived growth factor (PDGF) protein is reported. The aptasensor uses mixed self-assembled monolayers (SAMs) composed of a thiol-modified PDGF binding aptamer and 6-mercaptohexanol (MCH) on a gold electrode. The SAMs were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) before an...

The foregone studies have shown that nicotinic acid cannot produce noticeable reductive signal at carbon-based electrodes without appropriate modification of the electrode. This is an obvious reason that mercury is known as the main electrode material for electro-reduction of nicotinic acid. In this study, it has been shown that it is possible to create a remarkable reduction signal for NA at a...

A portable vacuum interface allowing direct probing of the electrode-electrolyte interface was developed. A classical electrochemical system consisting of a gold working electrode, platinum counter electrode, platinum reference electrode, and potassium iodide electrolyte was used to demonstrate real-time observation of the gold iodide adlayer on the electrode and chemical species as a result of...

A sensitive and selective differential pulse stripping voltammetric (DPSV) method is presented for the determination of trace amount Cr(III) using glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs). The method includes AuNPs fabrication and self-assembly GCE modification. This processes replaced the –H groups with –NH2 groups on the surfaces of GCE which increased the number...

The interactions of recombinant juvenile hormone binding protein (His8-rJHBP) with juvenile hormones (JHs), methoprene and farnesol have been studied with electrochemical impedance spectroscopy (EIS). The protein was immobilized on the dodecanethiol (DDT) modified gold electrodes. Each step of electrode modification has been confirmed with cyclic voltammetry (CV) and electrochemical impedance s...

The fabrication of novel uranyl (UO(2)(2+)) binding protein based sensors is reported. The new biosensor responds to picomolar levels of aqueous uranyl ions within minutes using Lysinibacillus sphaericus JG-A12 S-layer protein tethered to gold electrodes. In comparison to traditional self assembled monolayer based biosensors the porous bioconjugated layer gave greater stability, longer electrod...

An electrochemical sensor was developed by reconstituting pyrroloquinoline quinone (PQQ), flavin adenine dinucleotide (FAD) and L-proline dehydrogenase on gold electrode. Reversible redox peaks and low redox potential were obtained from cyclic voltammograms, proved that the attached PQQ and FAD accelerated electron communication between enzyme active site and gold electrode surface. It is expec...