Abstract: This invention provides a sensing device comprising an electrode comprising a noble metal layer, on which layer is located a biological material having nitroreductase activity. This invention further provides a method of detecting nitro group containing compounds, the method comprising the steps of: (a) providing a sensing device of the first aspect of the invention and a reference electrode; (b) applying a potential between the electrodes; (c) measuring the current; (d) contacting the sensing device with a sample of substrate material to be tested; and (e) measuring the current change.

Abstract: In a dielectrophoretic cell having an array of electrodes and means to apply electrical signals to the electrodes. The electrodes include a planar array of serpentine or zig-zag electrodes with their curvatures in register. The serpentine electrodes may be sinusoidal, half sinusoidal, or elongated “C” in shape. The positions of maximum curvature of each serpentine or zig-zag electrode may be arranged in linear alignment, or along a curve. The cell may be used for stationary or traveling wave dielectrophoresis. Particles traveling in opposite directions in traveling wave dielectrophoresis can do so without interference, allowing “traffic control”. Particles can be characterized and separated, and particles at high concentrations, or particles of different types, can be handled.

Abstract: In a method of manipulating particles suspended in a liquid medium, a moving standing wave ultrasonic vibration and an electrical field capable of generating a dielectrophoretic force on the particles are applied. The ultrasonic vibration may be applied to move the particles from a first suspending liquid to a second suspending liquid, or to move the particles into proximity with electrodes to apply the dielectrophoretic force, or to move the particles into the center of the liquid medium. Alternatively, the ultrasonic vibration and the electrical field may be applied simultaneously.

Abstract: This invention describes improvements in or relating to the production of polysaccharide derivatives; more particularly it relates to a method of converting insoluble polysaccharides to a form in which they form part of an anhydrous system in which they may be used as chemical intermediates in the production of derivatives.