Methods, systems, and devices are disclosed for providing test strip electrochemical sensors for rapid quantitative analysis of analytes in physiological fluids. In one aspect, an electrochemical sensor includes a substrate; an electrode contingent including a first electrode having a coating of carbon nanotubes (CNTs) and a second electrode on the substrate; and an entrapment layer formed on the first electrode to attach an enzymatic substance capable of causing a redox reaction in the presence of a target analyte of a fluid sample which produces a redox-active product, in which the entrapment layer is structured to include a conductive polymer film that is reversibly dopable to conduct charge carriers across the entrapment layer and at the first electrode. For example, the electrochemical sensor can be provided on a disposable test strip to quantify L-DOPA levels in whole blood, plasma, or serum samples.

Embodiments of this invention disclose new second generation uric acid-sensing electrodes at least characterized by chemically bonding both uricase and the redox mediator to an electrode. The produced electrodes can be long-term stably used without losing activity. The developed electrode has been successfully applied for the analysis of uric acid (UA) in healthy human urine specimens which exhibits very good analysis accuracy and precision without too much interference. Therefore, the developed electrodes have the potential for clinical applications.

An analyte sensor and a method for making the analyte sensor are disclosed. In one aspect, the analyte sensor includes a crosslinked, hydrophilic copolymer in contact with a surface of an electrode, and an analyte sensing component embedded within the crosslinked, hydrophilic copolymer. The method of making the analyte sensor includes depositing a precursor mixture containing monomers and an analyte sensing component onto an electrode, exposing the deposited precursor mixture to a controlled environment for a specified period of time, and photopolymerizing the deposited exposed precursor mixture into a copolymer layer in contact with a surface of the electrode. Exposing the deposited precursor mixture to a controlled environment can increase the sensitivity of the sensor by reducing the thickness of the copolymer layer and/or by causing the analyte sensitive component within the copolymer layer to have a non-uniform concentration within the layer.

In vivo monitoring devices and systems for enzymes and/or analytes including devices having a reactant reservoir are provided.

Compositions, devices, kits and methods are disclosed for assaying triglyceride with a glycerol 3-phosphate oxidase mutant. The glycerol 3-phosphate oxidase mutant has reduced oxidase activity while substantially maintaining, or increasing, its dehydrogenase activity, compared to the wild-type glycerol 3-phosphate oxidase.

Described herein are nucleic acid molecules and complexes useful as i-switch pH reporters that have increased sensitivities as a pH reporter and have alternate pH reporting capacity ranges. Aspects of the disclosure relate to a method for determining pH comprising providing a nucleic acid complex comprising: a first single-stranded nucleic acid molecule comprising the sequence C.sub.nXC.sub.nYC.sub.nZC.sub.n (SEQ ID NO. 6) wherein C is cytosine; X, Y and Z are each one or more of adenine, thymine, guanine, or combinations thereof; and n is greater than or equal to 2; and wherein at least 2 cytosine residues of the first single-stranded nucleic acid molecule are modified; and a second single-stranded nucleic acid molecule that is partially or fully complementary to the first single-stranded molecule, wherein a first label is conjugated to the first single-stranded nucleic acid molecule or the second single-stranded nucleic acid molecule; and wherein the first label is capable of producing a signal, wherein the intensity of the signal varies as a function of the conformation of the nucleic acid complex; and measuring the intensity of the signal and determining the pH from the measured signal.

A method of detecting a presence, amount and/or type of a pathogenic organism in a substrate is provided. The method is effected by contacting a sample suspected as containing the pathogenic organism or a portion thereof with an electrode, thereafter contacting the electrode with an aptamer that selectively binds to said pathogenic organism; thereafter contacting the electrode with an agent that participates in an electrochemically detectable reaction and thereafter perform the electrochemical reaction while using the electrode. The electric signal produced by the reaction is indicative of a presence and/or amount of the pathogenic organism. Also provided are a sensing system and kits usable for practicing the method, and use of the method for determining a suitable agent for reducing a load of a pathogenic organism in a substrate.

A method of calibrating a device for measuring the concentration of creatinine in a sample including one or more enzyme modulators, the method comprising: determining sensitivities of the device for each of two or more calibration solutions, wherein each calibration solution has a different amount of enzyme modulator; determining a degree of modulation for each of the two or more calibration solutions; determining a degree of modulation for a sample to be measured; and calculating the sensitivity of the device for the sample, wherein said calculating comprises modifying the sensitivity of one of the two or more calibration solutions by a function comprising the determined degrees of modulation.

The present disclosure relates to compositions, methods and test devices for determining the presence of active leukocyte cells, for example, by using novel LE and/or HNE substrates in an electrochemical assay.

The present disclosure provides devices, systems, and methods related to bioelectronic devices. In particular, the present disclosure provides bioelectronic devices, and methods of making bioelectronic devices, comprising adjustable adaptor polypeptides with repeatable motifs and enhanced conductive properties. The bioelectronic devices and methods of the present disclosure are useful for a variety of applications, including the direct measurement of protein activity (e.g., when sequencing a biopolymer).