The present invention relates to enzymes capable of hydrolysing organophosphate (OP) molecules. In particular, the invention relates to variants of the OpdA enzyme from Agrobacterium that display improved activity when compared to the naturally occurring OpdA. The invention is also towards polypeptides that have organophosphate hydrolysing activity for the organophosphates chlorpyrifos methyl, diazinon and parathion ethyl.

The disclosure discloses an enzyme electrode comprising; an electrode comprising a current collector; a monolayer-forming molecule bound to the surface of the current collector; and a glucose dehydrogenase comprising a cytochrome C subunit bound to the monolayer-forming molecule; wherein electrons are transferred between the glucose dehydrogenase and the current collector by oxidation-reduction reaction of the glucose dehydrogenase.

A system for the electrochemical detection of triglyceride levels includes a test strip including an electrode and a counter electrode, the electrode and counter electrode located proximate to a sample reception area; and a coating on one of the electrode and counter electrode, the coating including a reagent coating for triglycerides.

Devices, assays and methods for detecting analytes in a sample are provided. Biosensor devices include a biosensor interface that includes enzyme-conjugated molecules, antibodies and an enzyme driven redox cycle coupled to an electrically conductive electrode for signal amplification. The biosensor devices are easily adaptable to a variety of assay formats, a variety of target analytes and provide real-time measurements combined with high sensitivity and high specificity for the analyte.

The stiffness and topology of ultra-small circular DNAs and DNA/peptide hybrids are exploited to create a transducer of enzyme activity with low error rates. The modularity and flexibility of the concept are illustrated by demonstrating various transducers that respond to either specific restriction endonucleases or to specific proteases. In all cases the output is a DNA oligo signal that, as we show, can readily be converted directly to an optical readout, or can serve as input for further processing, for example, using DNA logic or amplification. By exploiting the DNA hairpin (or stem-loop) structure and the phenomenon of strand displacement, an enzyme signal is converted into a DNA signal, in the manner of a transducer. This is valuable because a DNA signal can be readily amplified, combined, and processed as information.

The present invention relates to systems, methods, and devices for determining the concentration of an analyte in a sample. The use of linear, cyclic, or acyclic voltammetric scans and/or semi-integral, derivative, or semi-derivative data treatment may provide for increased accuracy when determining the concentration of an analyte in a sample. Hematocrit compensation in combination with the data treatments may reduce the hematocrit effect with regard to a glucose analysis in whole blood. In another aspect, fast scan rates may reduce the hematocrit effect.

A system for the electrochemical detection of creatinine levels includes a test strip including an electrode and a counter electrode, the electrode and counter electrode located proximate to a sample reception area; and a coating on one of the electrode and counter electrode, the coating including a reagent coating for creatinine.

The present invention provides an arsenite oxidase enzyme modified to prevent translocation by modification of a translocation signal sequence. A microorganism modified to express the heterologous arsenite oxidase enzyme is also provided by the invention, together with a device for detecting the presence of arsenite in a sample.

This disclosure relates to creatinine biosensors and the uses thereof. More specifically, this disclosure describes potentiometric creatinine sensors which utilizes one or both of a type of enzyme capable of directly producing ammonium ions (NH4+) as a consequence of coming into contact with a liquid sample and an internal fill solution with a low free ammonium ion concentration.

A quantitation method of vitamin D derivative is provided including adding an oxidoreductase to a sample. The quantitation method of vitamin D derivative may further include reducing a mediator by adding the oxidoreductase, and reacting the reduced mediator with a reagent to determine a concentration of the vitamin D derivative.