An in vitro method for diagnosis, prognosis, risk assessment, monitoring, therapy guidance and/or therapy control of an infectious disease, includes (a.) providing a sample of a subject exhibiting clinical symptoms of and/or suspected of having an infection, (b.) determining a level of D-lactate in said sample, (c.) in which the level of D-lactate is indicative of the presence of an infectious disease, characterized in that (d.) the level of D-lactate in said sample is determined by means of an electrochemical sensing system (biosensor). In embodiments, the electrochemical sensing system includes a potentiometric or an amperometric sensor. Preferably, the electrochemical system includes a D-lactate binding molecule, that is preferably immobilized on a detection (working) electrode. In embodiments, the detection electrode with the immobilized D-lactate binding molecule is included by a (disposable) test strip for insertion into a portable reader.

The present disclosure provides an analyte sensor for use in detecting various analytes. In certain embodiments, an analyte-responsive active area of a presently disclosed analyte sensor includes two or more enzyme systems for detecting the analyte. The present disclosure further provides methods for detecting various analytes using the disclosed analyte sensors.

A sensor insertion device comprises a main body, needle slider, disposal slider, spring, puncture knob, and opening mechanism (window member and handle). The needle slider grips a needle and a sensor on a first end side, and is slidable inside the main body. The disposal slider is slidable inside the main body. The puncture knob has an insertion hole into which the rear end portion of the needle slider can be inserted. The opening mechanism puts the insertion hole into a closed state when the needle slider is being slid in the sensor insertion direction, and, puts the insertion hole in an open state in which the second end side of the needle slider has been inserted into the insertion hole by opening up the contact portion between the puncture knob and the second end side of the needle slider when the puncture operation is complete.

The present disclosure provides an analyte sensor for use in detecting glutamate. In certain embodiments, a glutamate-responsive active site of a presently disclosed analyte sensor includes an enzyme system comprising glutamate dehydrogenase and diaphorase disposed upon a surface of a working electrode. The present disclosure further provides methods for detecting glutamate using the disclosed analyte sensors.

The present disclosure provides devices, systems, and methods related to protein bioelectronics. In particular, the present disclosure provides devices, systems, and methods for forming electrical contacts to a protein with high yield, which facilitates the manufacture of analytical devices to detect and measure the electrical characteristics corresponding to protein function.

A new quantification method for measuring citrulline, which has an association with various diseases and is a biomarker particularly useful for early diagnosis of rheumatoid arthritis, an enzyme for quantification, a composition for quantification, and a kit for quantification are provided. A quantification method of citrulline is provided by adding a citrulline oxidoreductase to a sample. The oxidoreductase is an oxidase, and a concentration of the citrulline may be determined by quantifying hydrogen peroxide produced by addition of the oxidase. A concentration of the citrulline may be determined by reacting a reagent with hydrogen peroxide produced by addition of the oxidase.

The present disclosure provides an analyte sensor for use in detecting ketones. In certain embodiments, a ketones-responsive active site of a presently disclosed analyte sensor includes an enzyme system comprising β-hydroxybutyrate dehydrogenase and NADH oxidase disposed on a surface of a platinum working electrode. The present disclosure further provides methods for detecting ketones using the disclosed analyte sensors.

The present disclosure provides analyte sensors including one or more NAD(P)-dependent enzymes and an internal supply of NAD(P) for the detection of an analyte. The present disclosure further provides methods of using such analyte sensors for detecting one or more analytes present in a biological sample of a subject, and methods of manufacturing said analyte sensors.

A working electrode measuring the presence of an analyte is described as one embodiment. The working electrode includes a working conductor with a reactive surface that is operated at a first potential. The working electrode further includes a first transport material with properties that enable analyte flux to the reactive surface. Additionally, the working electrode has a second transport material with properties that enable reactant flux to the reactive surface, wherein the analyte flux and the reactant flux are in dissimilar directions.

According to one embodiment, a chemical sensor includes a sensor element. The sensor element includes a sensitive film and a treatment material. Physical properties of the sensitive film vary as bonding of a target substance to the sensitive film. The sensor element is configured to detect the variation in the physical properties. The treatment material is configured to carry out a treatment onto the target substance before the target substance bonds to the sensitive film. The treatment enhances the variation in the physical properties as compared to a case without the treatment.