An analyte monitor includes a sensor, a sensor control unit, and a display unit. The sensor has, for example, a substrate, a recessed channel formed in the substrate, and conductive material disposed in the recessed channel to form a working electrode. The sensor control unit typically has a housing adapted for placement on skin and is adapted to receive a portion of an electrochemical sensor. The sensor control unit also includes two or more conductive contacts disposed on the housing and configured for coupling to two or more contact pads on the sensor. A transmitter is disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the sensor. The display unit has a receiver for receiving data transmitted by the transmitter of the sensor control unit and a display coupled to the receiver for displaying an indication of a level of an analyte. The analyte monitor may also be part of a drug delivery system to alter the level of the analyte based on the data obtained using the sensor.

Analyte Monitoring Device And Methods Of Use

Wearable biosensors are garnering substantial interest due to their potential to provide continuous, real-time physiological information via dynamic, noninvasive measurements of biochemical markers in biofluids, such as sweat, tears, saliva and interstitial fluid. Recent developments have focused on electrochemical and optical biosensors, together with advances in the noninvasive monitoring of biomarkers including metabolites, bacteria and hormones. A combination of multiplexed biosensing, microfluidic sampling and transport systems have been integrated, miniaturized and combined with flexible materials for improved wearability and ease of operation. Although wearable biosensors hold promise, a better understanding of the correlations between analyte concentrations in the blood and noninvasive biofluids is needed to improve reliability. An expanded set of on-body bioaffinity assays and more sensing strategies are needed to make more biomarkers accessible to monitoring. Large-cohort validation studies of wearable biosensor performance will be needed to underpin clinical acceptance. Accurate and reliable real-time sensing of physiological information using wearable biosensor technologies would have a broad impact on our daily lives.

Wearable biosensors for healthcare monitoring.

http://cau.ac.kr/~jjang14/BioMEMS/Lazcka_BSBE_Pathogen_Detection_Review_2006.pdf

Pathogen detection: a perspective of traditional methods and biosensors.

Glucose oxidase: an ideal enzyme

Generation of reactive oxygen species (ROS) by the mitochondrial electron transport chain (ETC), which is composed of four multiprotein complexes named complex I-IV, is believed to be important in the aging process and in the pathogenesis of neurodegenerative diseases such as Parkinson's disease. Previous studies have identified the ubiquinone of complex III and an unknown component of complex I as the major sites of ROS generation. Here we show that the physiologically relevant ROS generation supported by the complex II substrate succinate occurs at the flavin mononucleotide group (FMN) of complex I through reversed electron transfer, not at the ubiquinone of complex III as commonly believed. Indirect evidence indicates that the unknown ROS-generating site within complex I is also likely to be the FMN group. It is therefore suggested that the major physiologically and pathologically relevant ROS-generating site in mitochondria is limited to the FMN group of complex I. These new insights clarify an elusive target for intervening mitochondrial ROS-related processes or diseases.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.0022-3042.2002.00744.x

Generation of reactive oxygen species by the mitochondrial electron transport chain

A phosphate-selective electrode based on immobilized alkaline phosphatase and glucose oxidase.

A report on the status of the quartz crystal microbalance (QCM) technique for applications in biochemistry, food, environmental and clinical analysis is presented. With the advent of pre-coated crystals, used in a flow cell with the microprocessor controlled PZ 106 Immunobiosensor System, assays can be performed with the QCM in a manner equivalent to the SPR (surface plasmon resonance) technique both in sensitivity and selectivity. ∗Humboldt Fellow on Leave from the University of New Orleans, Louisiana 70148 (USA).

The Quartz Crystal Microbalance as Biosensor. A Status Report on Its Future

An electrode for determination of amino acids.

Piezoelectric crystal biosensors.

We describe a fluorometric enzymatic method for determining total serum cholesterol, based on hydrolysis of cholesterol esters to free cholesterol by cholesterol ester hydrolase (EC 3.1.1.13). The free cholesterol formed, as well as that initially present, is then oxidized by cholesterol oxidase (EC 1.1.3.6) to cholest-4-en-3-one with simultaneous production of hydrogen peroxide. The latter catalytically oxidizes homovanillic acid in the presence of peroxidase (EC 1.11.1.7) to form the highly fluorescent 2,2'-dihydroxy-3,3'-dimethoxy-biphenyl-5,5'-diacetic acid. A calibration curve is constructed from data on a series of standard cholesterol solutions vs. the corresponding fluorescence change (deltaf/5 min). This curve is linear up to 4.0 g of total serum cholesterol per liter of serum. The method is specific, precise, accurate, rapid, and simple, and results correlate well with those obtained by both the Liebermann-Burchard procedure and the colorimetric enzymatic method (correlation coefficients, 0.984 and 0.981, respectively).

George G. Guilbault

Papers

A phosphate-selective electrode based on immobilized alkaline phosphatase and glucose oxidase.

The Quartz Crystal Microbalance as Biosensor. A Status Report on Its Future

An electrode for determination of amino acids.

Piezoelectric crystal biosensors.

Fluorometric enzymatic determination of total cholesterol in serum.