A simple visual ethanol biosensor based on alcohol oxidase (AOX) immobilised onto polyaniline (PANI) film for halal verification of fermented beverage samples is described. This biosensor responds to ethanol via a colour change from green to blue, due to the enzymatic reaction of ethanol that produces acetaldehyde and hydrogen peroxide, when the latter oxidizes the PANI film. The procedure to o...

The optimization-based quantitative determination of multianalyte concentrations from biased biosensor responses is investigated under internal and external diffusion-limited conditions. A computational model of a biocatalytic amperometric biosensor utilizing a mono-enzyme-catalyzed (nonspecific) competitive conversion of two substrates was used to generate pseudo-experimental responses to mixt...

Pseudomonas fluorescens cultures produce fluorescent siderophores. By utilizing optimal conditions for maximizing siderophore production in shake flask cultures of P. fluorescens, we report successful characterization of the culture broth supernatant as a robust ferric ions biosensor. For characterizing the ferric ions biosensor, we tested the effects of pH, buffers, different ferric salts and ...

Using a mean-field theory, we have studied the quantum extension on the limiting current density in a crossed-field nanogap. When the gap spacing is less than the electron wavelength, our results show that the limiting current density is increased by a large factor from the classical values due to the effects of electron tunneling. The effects of the external magnetic field diminish with a decr...

We present real-time transmission electron microscopy of nanogap formation by feedback controlled electromigration that reveals a remarkable degree of crystalline order. Crystal facets appear during feedback controlled electromigration indicating a layer-by-layer, highly reproducible electromigration process avoiding thermal runaway and melting. These measurements provide insight into the elect...

Microelectrode amperometric biosensors are widely used to measure concentrations of analytes in solution and tissue including acetylcholine, adenosine, glucose, and glutamate. A great deal of experimental and modeling effort has been directed at quantifying the response of the biosensors themselves; however, the influence that the macroscopic tissue environment has on biosensor response has not...

Magnetic nanoparticles of Fe₃O₄ were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe₃O₄ nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe₃O₄ nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the subs...

Nanogaps functionalized with small diamond-like particles, diamondoids, have been shown to effectively distinguish between different DNA nucleotides. Here, we focus on the detection of mutations and epigenetic markers using such devices. Based on quantum mechanical simulations within the density functional theory approach coupled with the non-equilibrium Green’s function scheme, we provide deep...