Ascorbic acid sensor using a PVA/laccase-Au-NPs/Pt electrode.

A surface-modified electrode, PVA/laccase-Au-NPs/Pt, was prepared to sense ascorbic acid (HA) in this study. An amount of the following composite, PVA/laccase-Au-NPs/Pt, the polyvinyl acetate (PVA) was employed as a surfactant to adhere the substrate, Pt; then the laccase peptides were spun inside the PVA fiber to wind around the immobilized Au-NPs and construct a hierarchical structure. The PVA shell layer was in charge of sensing HA and transmitting electrical signals, transducing redox reaction of HA.

Ruthenium oxide modified nickel electrode for ascorbic acid detection.

Electrodes of ruthenium oxide modified nickel were prepared by a thermal decomposition method. The stoichiometry of the modifier, RuO, was quantitatively determined to be a meta-stable phase, RuO. The electrodes were employed to sense ascorbic acid in alkaline solution with a high sensitivity, 296 μAcm mM, and good selectivity for eight kinds of disturbing reagents.

Telemetric electrochemical sensor.

A telemetric system was designed and constructed to sense pH and ethanol variation in aqueous solutions. The measured signals were transferred by software digitally and transmitted wirelessly by the telemeter, personal digital assistant (PDA), through the General Packet Radio Service (GPRS) protocol. The pH sensing electrode was designed to measure a chemical potential induced by a proton concentration gradient on the electrode's surface which exhibits internal Donnon diffusion behavior, and a linear relationship between the electrical potential and pH was found.

Ionic liquid ethanol sensor.

Ionic liquids containing lithium methylsulfonyl group were prepared from the precursors poly(propylene glycol)-block-(ethylene glycol)-block-(propylene glycol)-bis(2-aminopropyl ether) with different molecular weight. These liquids revealed excellent electrical conductivity in the temperature range -25 to 85 degrees C. Also, they exhibited a high boiling temperature and hence a low vapor pressure in ambient condition.