| 单词 | biosensor |
| 释义 | biosensorenUKbi·o·sen·sorB0269100 (bī′ō-sĕn′sər, -sôr)biosensor(ˈbaɪəʊˌsɛnsə)biosensorenUKBiosensorAn integrated device consisting of a biological recognition element and a transducer capable of detecting the biological reaction and converting it into a signal which can be processed. Ideally, the sensor should be self-contained, so that it is not necessary to add reagents to the sample matrix to obtain the desired response. There are a number of analytes (the target substances to be detected) which are measured in biological media: pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), and the ionic concentrations of sodium, potassium, calcium, and chloride. However, these sensors do not use biological recognition elements, and are considered chemical sensors. Normally, the biological recognition element is a protein or protein complex which is able to recognize a particular analyte in the presence of many other components in a complex biological matrix. This definition has since been expanded to include oligonucleotides. The recognition process involves a chemical or biological reaction, and the transducer must be capable of detecting not only the reaction but also its extent. An ideal sensor should yield a selective, rapid, and reliable response to the analyte, and the signal generated by the sensor should be proportional to the analyte concentration. Biosensors are typically classified by the type of recognition element or transduction element employed. A sensor might be described as a catalytic biosensor if its recognition element comprised an enzyme or series of enzymes, a living tissue slice (vegetal or animal), or whole cells derived from microorganisms such as bacteria, fungi, or yeast. The sensor might be described as a bioaffinity sensor if the basis of its operation were a biospecific complex formation. Accordingly, the reaction of an antibody with an antigen or hapten, or the reaction of an agonist or antagonist with a receptor, could be employed. In the former case, the sensor might be called an immunosensor. Since enzyme-based sensors measure the rate of the enzyme-catalyzed reaction as the basis for their response, any physical measurement which yields a quantity related to this rate can be used for detection. The enzyme may be immobilized on the end of an optical fiber, and the spectroscopic properties (absorbance, fluorescence, chemiluminescence) related to the disappearance of the reactants or appearance of products of the reaction can be measured. Since biochemical reactions can be either endothermic (absorbing heat) or exothermic (giving off heat), the rate of the reaction can be measured by microcalorimetry. Miniaturized thermistor-based calorimeters, called enzyme thermistors, have been developed and widely applied, especially for bioprocess monitoring. In the case of affinity biosensors, as is true of catalytic biosensors, many physical techniques can be used to detect affinity binding: microcalorimetry (thermometric enzyme-linked immunosorbent assay, or TELISA), fluorescence energy transfer, fluorescence polarization, or bioluminescence. The quality of the results obtained from sensors based on biological recognition elements depends most heavily on their ability to react rapidly, selectively, and with high affinity. Antibodies and receptors frequently react with such high affinity that the analyte does not easily become unbound. To reuse the sensor requires a time-consuming regeneration step. Nonetheless, if this step can be automated, semicontinuous monitoring may be possible. biosensor[¦bī·ō¦sen·sər]biosensorA device that detects a person's body movement, temperature, pulse rate and other physical characteristics, which it converts into electronic signals. See lab on a chip, smart clothes, biowearable and data glove.biosensorenUKbiosensor(bī′ō-sĕn′sər, -sôr)biosensor(1) A sensor which collects data on a biologic or physiologic process—e.g., blood pressure, temperature, etc.(2) A biomolecule or system—e.g., enzyme, receptor, antibody, organelle or cell—coupled to a microelectronic system or optical probe to enable rapid, accurate, low-level detection of substances in body fluids, water and air. Biosensors have been used to measure glucose, creatinine, ethanol, gamma globulin, lidocaine, nerve gases, penicillin, sodium ions, testosterone, theophylline, vitamin B12, and O2. biosensor(bī′ō-sen″sor″) [ bio- + sensor]biosensora biological material such as an ENZYME, an ANTIBODY, a MICROORGANISM or other biological system, coupled to an appropriate transducing system, which act together to monitor a specific biochemical reaction and convert it into a measurable electrical signal. Biosensors may be used in health care, for example to measure specific METABOLITES in the body, and in the monitoring of pollutants in the environment. The enzyme glucose oxidase is used in the biosensor for monitoring GLUCOSE levels in the blood. |
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