A composition for detecting an analyte in a blood sample includes: a coloring reagent; an oxidoreductase; and a refractive index adjuster.

Sensors comprising B-L-S; wherein: B is a biomolecule comprising one or more surface-exposed thiol moieties, L is a thiol reactive linking group, and S is a substrate; wherein L is covalently linked to B via the one or more surface-exposed thiol moieties.

An apparatus for non-invasively estimating a biological component is provided. The apparatus may include: a sensor configured to measure a calibration spectrum for a first duration and measure a biological component estimation spectrum for a second duration, based on light returning from an object; and a processor configured to remove a signal of a biological component from the calibration spectrum to obtain a background spectrum for the first duration, and estimate the biological component, based on the background spectrum and the biological component estimation spectrum, for the second duration in response to a command for measuring the biological component.

An apparatus for non-invasively estimating a biological component is provided. The apparatus may include: a sensor configured to measure a calibration spectrum for a first duration and measure a biological component estimation spectrum for a second duration, based on light returning from an object; and a processor configured to remove a signal of a biological component from the calibration spectrum to obtain a background spectrum for the first duration, and estimate the biological component, based on the background spectrum and the biological component estimation spectrum, for the second duration in response to a command for measuring the biological component.

A method for determining in a sample, by mass spectrometry, the amount of one or more analytes selected from the group consisting of N-acetylthreonine, TMAP, phenylacetylglutamine, tryptophan, creatinine, meso-erythritol, arabitol, myo-inositol, N-acetyl serine, N-acetylalanine, 3-methylhistidine, trans-4-hydroxyproline, kynurenine, urea, C-glycosyltryptophan, 3-indoxyl sulfate, pseudouridine, and combinations thereof is described. The method comprises subjecting the sample to an ionization source under conditions suitable to produce one or more ions detectable by mass spectrometry from each of the one or more of the analytes; measuring, by mass spectrometry, the amount of the one or more ions from each of the one or more analytes; and using the measured amount of the one or more ions to determine the amount of each of the one or more analytes in the sample. Also described is a kit comprising one or more isotopically labeled analogues as internal standards for each of the one or more analytes.

Described are compositions and methods for determining the propensity of a subject with diabetes (e.g., type 1 diabetes) to benefit from treatment with Bacillus Calmette-Guerin (BCG). Using the compositions and methods of the disclosure, a subject with diabetes (e.g., type 1 diabetes) may be identified as likely to respond to BCG therapy on the basis, for example, of a determination that the subject was young (e.g., less than 40 years of age) at the time of onset of the diabetes. Additionally, or alternatively, the subject may be identified as likely to respond to BCG therapy based on a determination that the subject exhibits a reduced rate of glucose uptake, an elevated rate of oxidative phosphorylation, and/or a reduced rate of aerobic glycolysis, for example, as compared to a healthy subject (e.g., a subject without diabetes). The compositions and methods of the disclosure can additionally be used to administer BCG to subjects identified as likely to respond to treatment with a composition comprising BCG.

Disclosed are devices for determining an analyte concentration (e.g., glucose). The devices comprise a sensor configured to generate a signal associated with a concentration of an analyte and a sensing membrane located over the sensor. The sensing membrane comprises an enzyme layer, wherein the enzyme layer comprises an enzyme and a polymer comprising polyurethane and/or polyurea segments and one or more zwitterionic repeating units. The enzyme layer protects the enzyme and prevents it from leaching from the sensing membrane into a host or deactivating.

Disclosed are devices for determining an analyte concentration (e.g., glucose). The devices comprise a sensor configured to generate a signal associated with a concentration of an analyte and a sensing membrane located over the sensor. The sensing membrane comprises an enzyme layer, wherein the enzyme layer comprises an enzyme and a polymer comprising polyurethane and/or polyurea segments and one or more zwitterionic repeating units. The enzyme layer protects the enzyme and prevents it from leaching from the sensing membrane into a host or deactivating.

There is described a process for improving precision in an analytical test for a target analyte in a sample. The process includes prior to analyzing the sample for a target analyte via a biosensor, introducing to an analytical zone defined by the biosensor fluid comprising an effective amount of the target analyte.

A portable apparatus for measuring a glucose level of a user having: a card-like member; a processor within the card-like member; at least one glucose sensor comprising a reagent, the glucose sensor generating a signal indicative of a measured glucose level upon application of a blood sample to the glucose sensor, wherein the glucose sensor is fixed to the card-like member and operably coupled to the processor; and at least one cover alterable between a first position in which the glucose sensor is covered and a second position in which the glucose sensor is exposed for use.