Immunosensors structure

In an immunosensor the core-cover interface of an optical waveguide structure is coated with a chemo-optical transducer receptor layer, which can selectively bind to specific analyte molecules present in the cover medium. The receptor-analyte reaction obeys the law of mass action, which states that the rate of a reaction is proportional to the concentration of the reactants. At equilibrium, the rate of formation of the receptor-analyte complex is equal to the rate of breaking, and the equilibrium constant, K. can be written as... 

Briand E, Sabnain M, Henry JM et al (2006) Building of an immunosensor how can the composition and structure of the thiol attachment layer affect the immunosensor efficiency Biosens Bioelectron 22(3) 440-448... 

Currently, immunosensors provide a powerful tool for monitoring biospecific interactions in real time or for deriving information about the binding kinetics of an immunoreaction or the structure/function relationships of molecules. Amperometric, potentiometric, conductive, and impedimetric transducers have been applied in direct and indirect electrochemical immunoassays. 

Song, Z., Yuan, R.,et al. Multilayer structured amperometric immunosensor based on gold nanoparticles and Prussian blue nanopaiticlesAianocomposite functionalized interface. Electrochimica Acta,55(5), 1778-1784 (2010). 

It is generally considered that Abs bind their Ags with high specificities. However, both polyclonal and monoclonal Abs in general will bind (with varying degrees of affinity) to compounds structurally related to the antigen. In particular, for small molecular weight haptens, polyclonal antibodies may be directed toward the protein used as the carrier as well as to the hapten and chemical structure used to link them. This is an important consideration for certain immunosensor assay formats. 

Impedimetric measurements are inherently nonselective, but the modification of electrode surfaces with selective recognition agents has resulted in selective sensing devices based on impedimetric transducers. Reviews of immunosensors and cell-based biosensors include sections on impedance transduction [177, 250, and references therein]. A review of bioelec-tronic noses, devices intended to mimic the human olfactory system in detecting and identifying odors, includes interdigital structures for complex impedance measurements and arrays of capacitive sensor elements [251]. 

The brief discussion presented suggests that tanplate-synthesized porous carbons with carefully controlled pore structure may soon find applications in the immobilization of biomolecules (proteins, enzymes, and vitamins) and in bioconversion, reversible amperometric immunosensors, regeneration of enzyme electrodes, switchable biofuel cells, and artificial kidneys [359]. 

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