Label-free aptasensors electrochemical aptasensor development

As an example of application of electrochemical aptasensor to medical diagnosis. Sun et al. developed a label-free electrochemical aptasensor for thrombin detection in whole blood. For the fabrication of this aptamers, self-assembled multilayers of carboxymethyl-polyethylene glycol-carboxymethyl (CM-PEG-CM) and thrombinbinding aptamer (TBA) were used. The thrombin molecules in the medium bound onto the TBA which leads to current decrease. This current decrease was monitored by differential pulse voltammetry. A linear range of 1 pM to 160nM was obtained for thrombin with LOD value of 1.56 x (Sun et al., 2013). 

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