A photonic crystal optical biosensor is incorporated into standard format 96-well microplates for the purpose of detecting the attachment of cells to the biosensor surface without the use of fluorescent labels or any other type of marker. We show that the attachment of cells to the biosensor can be modulated by the immobilization of cognizant ligands to the sensor surface that selectively recog...

Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD). In the present study, we developed a highly sensitive, cell-based biosensor to detect treha...

To investigate quorum sensing in rhizosphere soil, a whole-cell biosensor, Agrobacterium tumefaciens(pAHL-Ice), was constructed. The biosensor responded to all N-acyl homoserine lactones (AHLs) tested, except C(4) homoserine lactone, with a minimum detection limit of 10(-12) M, as well as to both exogenously added AHLs and AHL-producing bacterial strains in soil. This highly sensitive biosensor...

Reaction between the NH4VO3 and pyridoxal semicarbazone (PLSC) in a methanol/ammonia solution forms an orange, diamagnetic, mononuclear NH4[VO2(PLSC-2H)] complex in which vanadium is in the oxidation state +5, and pyridoxal semicarbazone is coordinated in its dianionic form. The complex cocrystallizes with a neutral molecule of PLSC and two water molecules. The coordination environment around v...

Chemiresistors (conductometric sensor) were fabricated on the basis of novel nanomaterials--silica nanosprings ALD coated with ZnO. The effects of high temperature and UV illumination on the electronic and gas sensing properties of chemiresistors are reported. For the thermally activated chemiresistors, a discrimination mechanism was developed and an integrated sensor-array for simultaneous rea...

One dimensional polyaniline nanowire is an electrically conducting polymer that can be used as an active layer for sensors whose conductivity change can be used to detect chemical or biological species. In this review, the basic properties of polyaniline nanowires including chemical structures, redox chemistry, and method of synthesis are discussed. A comprehensive literature survey on chemires...

Conductometric gas sensors made of gas permeable metal oxide ultrathin membranes can combine the functions of a selective filter, preconcentrator, and sensing element and thus can be particularly promising for the active sampling of diluted analytes. Here we report a case study of the electron transport and gas sensing properties of such a membrane made of nanoporous Ta₂O₅. These membranes demo...

Anionic capillary isotachophoresis (cITP) with conductometric detection was used for indirect determination of neomycin trisulphate (NMS) as sulphate anion. The following electroylets were tested: leading (LE)--8 mM HCl adjusted with beta-alanine to pH = 3.55, 3 mM bis-tris-propane and 0.2% hydroxyethylcellulose and terminating (TE): 5 mM citric acid; 5 mM formic acid and 5 mM caproic acid. The...

A conductometric sensor based on screen-printed interdigital gold electrodes on glass substrate coated with molecularly imprinted polyurethane layers was fabricated to detect polycyclic aromatic hydrocarbons (PAHs) in water. The results prove that screen-printed interdigital electrodes are very suitable transducers to fabricate low-cost sensor systems for measuring change in resistance of PAH-i...