The simultaneous fluctuations of potential noise and current noise between two nominally identical X-65 mild steel electrodes were recorded using a ZRA (Zero Resistance Ammeter) to monitor localized CO2 corrosion in CO2-saturated 1 wt % NaCl solution at 80C. Electrochemical noise (EN) was obtained from both 11.6 cm and 1 cm specimens to understand how the surface area affects EN signals. Linear...

Impedance sensing of biological systems allows for monitoring of cell and tissue properties, including cell-substrate attachment, layer confluence, and the "tightness" of an epithelial tissue. These properties are critical for electrical detection of tissue health and viability in applications such as toxicological screening. Organic transistors based on conducting polymers offer a promising ro...

−− The use of Quartz Crystal Oscillators (QCM) as high accuracy microbalance sensors is limited by the frequency noise present in the circuit. This work deals with the design and implementation of an FPGA-based system for the real-time measurement of the frequency noise and resolution of QCM sensors. This reconfigurable system integrates the frequency measurement and the mass resolution computa...

A novel microchip capillary electrophoresis system with electrochemical detection, using the replaceable microelectrode, is first reported. This kind of electrode can be fabricated in general laboratories and can be replaced quickly with electrodes of different materials according to the requirements of experiments. The end-column electrochemical detection on microchip CE was achieved by fixing...

We evaluate the RC-time of edge states capacitively coupled to a gate located away from a QPC which allows for partial transmission of an edge channel. At long times or low frequencies the RC-time governs the relaxation of charge and current and governs the fluctuations of the equilibrium electrostatic potential. The RC-time in mesoscopic structures is determined by an electrochemical capacitan...

A simple microprocessor controlled mini-electrochemical (EC) instrument integrating with square wave voltammetry (SWV) was designed nd fabricated. Direct digital frequency synthesizer (DDFS) was exploited in the circuit design to generate a linear and very low frequency canning waveform for SWV. An ultra-low bias current, a high performance operational amplifier, a lock-in amplifier, and severa...

Here, we report development of the galvanostatic Fourier transform electrochemical impedance spectroscopy (FTEIS), which monitors impedance of electrochemical reactions activated by current steps. We first derive relevant relations for potential change upon application of a step current, obtain impedances theoretically from the relations by simulation, and verify them with experimental results....

A novel electrochemical cell has been designed and built to allow for in situ energy-dispersive X-ray diffraction measurements to be made during reduction of UO2 to U metal in LiCl-KCl at 500°C. The electrochemical cell contains a recessed well at the bottom of the cell into which the working electrode sits, reducing the beam path for the X-rays through the molten-salt and maximizing the signal...

An automatic, reliable, scanning reductive electrochemical detection system is described for on-line qualitative and semi-quantitative determination and characterization of electro-active compounds in effluentsfrom high-performance liquid chromatographic (HPLC) systems. Applying a static mercury drop electrode, detection can be performed at constant potential for quantitative analysis (current ...

A simple and accurate label-free amperometric immunosensor for α-fetoprotein (AFP) detection is developed based on gold nanorods (GNRs) with different aspect ratio and compared with gold particles (GNPs). The positively charged GNRs and GNPs due to the surface immobilized cetyltrimethyl ammonium bromide (CTAB) can adsorb the negatively charged AFP antibody (Ab) directly. The presence of the GNR...