Antibodies biochemical sensors

Sensitive, selective detection of biochemically active compounds can be achieved by employing antigen-antibody, enzyme-substrate, and other receptor-protein pairs, several of which have been utilized in the development of piezoelectric immunoassay devices. The potential analytical uses of these materials has been reviewed, particularly with respect to the development of biochemical sensors [221-224], The receptor protein (e.g., enzyme, antibody) can be immobilized directly on the sensor surface, or it can be suspended in a suitable film or membrane. An example of the sensitivity and response range that can be... 

Two immunosensors developed by O Regan et al. [89,90] have demonstrated their usefulness for the early assessment of acute myocardial infarction (AMI). Human heart fatty-acid binding protein (H-FABP) is a biochemical marker for the early assessment of AMI. The authors constructed an amperometric immunosensor for the rapid detection of H-FABP in whole blood. The sensor is based on a one-step, direct sandwich assay in which the analyte and an alkaline phosphatase (AP) labelled antibody are simultaneously added to the immobilized primary antibody, using two distinct monoclonal mouse anti-human H-FABP antibodies. The substrate p-amino-phenyl phosphate is converted to p-aminophenol by AP, and the current generated by its subsequent oxidation at +300 mV vs. Ag/AgCl is measured. The total assay time is 50 min, and the standard curve was linear between 4 and 250 ng ml . The intra- and inter-assay coefficients of variation were below 9%. No cross-reactivity of the antibodies was found with other early cardiac markers, and endogenous substances in whole blood did not have an... 

Fluorescent probes have been extremely useful in elucidating biochemical mechanisms and processes inside of living cells via fluorescent microscopy. This technique is particularly valuable because it is non-destructive and the probes can be observed in real time over the course of cellular events. Fluorescent probes fall into two main classes chemosensors and biosensors. Biosensors are fluorescently labelled proteins, most often antibodies. These types of probes have the disadvantage of poor cell permeability, but can be generated with specificity for any macromolecule against which an antibody can be raised. Chemical sensors are typically based on synthetic compounds and have been used in cells mainly to quantify the concentration of certain... 

Nevertheless, a steady rapid development of immunotests can be observed, especially in the field of environmental monitoring [l]-[3], where the question of costs has become so important that the establishment of an immunotest can be worthwhile in spite of all the facts mentioned above. In the development of chemical sensors, efforts are also being made to utilize the biochemical recognition principle by coupling with optical, electrochemical, or other transducer (signal transfer) [4] - [6]. However, the slower kinetics involved in molecular biological processes require stricter maintenance of the experimental protocol, e.g., the time of reaction between the antibody and the tracer molecule or analyte (hapten) should be set up in an exactly reproducible manner by means of flow-injection analysis 7],... 

Utilize a biochemical mechanism for recognition. They are responsible for binding the analyte of interest to the sensor surface for the measurement. Bioreceptors can generally be classified into five major categories enzyme, antibody/antigen, nucleic acid/DNA, cellular structure/ceU, and biomimetic. The sampling component of a biosensor contains a biosensitive layer that can contain bioreceptors or be made of bioreceptors cova-lendy attached to the transducer. The most common forms of bioreceptors used in biosensing are based on ... 

Chemical sensors can be of gas, liquid, and solid particulate sensors based on the phases of the analyte. Depending on the operating principle of transducer in a chemical sensor, it can be used as optical, electrochemical, thermometric, and gravimetric sensor. Chemical sensors also include a special branch referred to as biosensors for the recognition of biochemicals and bio-reactions. The use of biological elements such as organisms, enzymes, antibodies, tissues, and cells as receptors differentiates biosensors from conventional chemical sensors. 

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