In this paper, we design and implement a portable potentiostat by using dual-microprocessors for the signal processing of electrochemical biosensors. In our design approach, one of the microprocessors is used to design the programmable waveform generator, and the other microprocessor is used to measure the current of biosensors. The proposed potentiostat can perform general electrochemical anal...

Formation of a fusion pore between a vesicle and its target membrane is thought to involve the so-called SNARE protein complex. However, there is no mechanistic model explaining how the fusion pore is opened by conformational changes in the SNARE complex. It has been suggested that C-terminal zipping triggers fusion pore opening. A SNAP-25 mutant named SNAP-25Delta9 (lacking the last nine C-ter...

The roles of nonmuscle myosin II and cortical actin filaments in chromaffin granule exocytosis were studied by confocal fluorescence microscopy, amperometry, and cell-attached capacitance measurements. Fluorescence imaging indicated decreased mobility of granules near the plasma membrane following inhibition of myosin II function with blebbistatin. Slower fusion pore expansion rates and longer ...

A non-enzymatic amperometric glucose biosensor based on a modified electrode was fabricated by electrochemical derivatization of copper hexacyanoferrate (CuHCF) film at gold nanoparticles (GNP) adsorbed graphite wax composite electrode. The modified electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The electrode was also characterized by scannin...

Lipid molecules such as arachidonic acid (AA) and sphingolipid metabolites have been implicated in modulation of neuronal and endocrine secretion. Here we compare the effects of these lipids on secretion from cultured bovine chromaffin cells. First, we demonstrate that exogenous sphingosine and AA interact with the secretory apparatus as confirmed by FRET experiments. Examination of plasma memb...

AIM Pseudomonas aeruginosa is a pathogen that is prevalent in serious infections in compromised patients worldwide. A unique virulence factor of this bacterium is the redox-active molecule pyocyanin, which is a potential biomarker for the identification of P. aeruginosa infections. Here we report a direct, selective and rapid detection technique of pyocyanin. MATERIALS & METHODS Pyocyanin was...

This paper describes the first immunosensing system reported for the detection of bacteria combining immunomagnetic capture and amperometric detection in a one-step sandwich format, and in a microfluidic environment. Detection is based on the electrochemical monitoring of the activity of horseradish peroxidase (HRP), an enzyme label, through its catalysis of hydrogen peroxide (H(2)O(2)) in the ...

A rapid prototyping of an inexpensive, disposable graphene and copper nanocomposite sensor strip using polymeric flexible substrate for highly sensitive and selective nonenzymatic glucose detection has been developed and tested for direct oxidization of glucose. The CuNPs were electrochemically deposited on to the graphene sheets to improve electron transfer rates and to enhance electrocatalyti...

Given the growing interest in porcine islets as model tissue for studying the pathogenesis of human diabetes mellitus and its treatment by transplantation, we investigated stimulus-exocytosis coupling in single porcine beta-cells using patch clamp electrophysiology, Ca2+ imaging, capacitance tracking and amperometry. We establish that porcine beta-cells display several features prominently seen...

Nanostructures Chengzhou Zhu,†,§ Guohai Yang,†,§ He Li,†,§ Dan Du,† and Yuehe Lin*,†,‡ †School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, United States ‡Pacific Northwest National Laboratory, Richland, Washington 99352, United States ■ CONTENTS Nonenzymatic Sensors 231 Glucose 231 Hydrogen Peroxide 231 Cation 232 Anion 232 Other Species 232 ...