A disposable test cartridge to determine the concentration of one or more liver enzymes in a blood sample includes a cartridge body having a plurality of chambers where at least one of the chambers contains a reactant mixture that reacts when catalyzed by one of the liver enzymes ALT, AST, ALP, or GGT in a blood sample forming a reaction solution, a removable cartridge cover connected to the cartridge body, and a test strip module connected to the cartridge body. The test strip module containing at least one analyte test strip configured for receiving a portion of the reaction solution and electrochemically measuring at least one analyte that is a reaction product in the reaction solution.

A reagent for detecting an analyte comprises a flavoprotein enzyme, a mediator such as a phenothiazine mediator, at least one surfactant, a polymer and a buffer. The reagent may be used with an electrochemical test sensor that includes a plurality of electrodes.

In various embodiments a molecular circuit is disclosed. The circuit comprises a negative electrode, a positive electrode spaced apart from the negative electrode, and an enzyme molecule conductively attached to both the positive and negative electrodes to form a circuit having a conduction pathway through the enzyme. In various examples, the enzyme is a polymerase. The circuit may further comprise molecular arms used to wire the enzyme to the electrodes. In various embodiments, the circuit functions as a sensor, wherein electrical signals, such as changes to voltage, current, impedance, conductance, or resistance in the circuit, are measured as substrates interact with the enzyme.

Herein is reported a method for the detection of a sortase in a sample, comprising the following steps: a) incubating the sample with a first substrate comprising an immobilization tag and a second substrate comprising a detectable label, whereby in the presence of a sortase in the sample a conjugate comprising the immobilization tag and the detectable label is formed, b) immobilizing the conjugate of step a) via/using the immobilization tag to a solid phase, c) detecting the immobilized conjugate via/using the detectable label
and thereby detecting the sortase in the sample.

An enzymatic electrochemical sensor for the detection of blood propofol is provided.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

A sensor implanted in tissues and including a sensing layer is fabricated by mixing the signal transduction enzyme with non-reactive components including buffer salts and fillers, and spin coating the enzyme onto a substrate. The signal transduction enzyme is crosslinked by introducing the coated substrate in a vacuum chamber. In the chamber, a crosslinker evaporates and is deposited onto the enzyme, therefore crosslinking the enzyme.

A method is provided for determining, the presence and concentration of an analyte by contacting the sample with a solution comprising: magnetic beads, a capture probe capable of binding the analyte, a reporter probe and cellulose, whereby, if the analyte is present, an MB-analyte-reporter-cellulase sandwich is formed; and then contacting the solution comprising the sandwich with an electrode covered with an electrically insulating layer comprising or consisting of cellulose and/or a cellulose derivative, wherein the MB-analyte-reporter-cellulase sandwich leads to degradation of the insulating layer thereby causing a measurable change in electrical properties at the electrode surface, wherein the change in electrical properties is a function of the amount of analyte in the sample. Devices and biosensor applying the method are also provided.

An electrochemical test for total cholesterol includes a test strip for an electrochemical testing testing of a blood analyte which includes a first receiving port, the first receiving port for receiving a blood sample, the first receiving port at a first end of the test strip. The test strip further includes a first electrode and a second electrode, the first and second electrodes proximate to the first receiving port. The test strip further includes a first contact and a second contact, the first and second contacts at a second end of the test strip, the first and second contacts interconnected with the first and second electrodes, respectively. The test strip further includes cholesterol oxidase, located proximate to the first and the second electrode. The test strip further includes a mediator, located proximate to the first and the second electrode, wherein the cholesterol oxidase and the mediator interact with the blood sample and the first and second electrode to generate a measurable electrical event.