Aptamers, biosensor therapeutics

With respect to their application, aptamers were selected in the past mainly for their use as therapeutic agents. In addition to the therapeutic field, aptamers have been then used in several analytical methodologies, such as affinity chromatography, capillary electrophoresis (14), mass spectrometry (15), or biosensors (1). These aptamers-based methods have been mainly employed in the clinical area for the development of diagnostic assays. 

We are presently in the early days of the emerging technology of using aptamers and nanomaterials to modify biosensors. So far, thrombin-binding aptamer has been the topic of numerous reports, but although many improvements are required in reproducibility and sensitivity, there is no doubt that a growing number of aptamers and, it is to be hoped, nanomaterial-based label-free aptasensors will soon be used for the diagnosis and therapeutic follow-up of diseases. 

One of the most preeminent examples of the in vitro selection of DNA oligonucleotides for targeting a specific protein is the thrombin-binding aptamer (TBA). Thrombin is a serine protease and a coagulation protein in the blood stream that has many effects in the coagulation mechanism. Because of its importance in anticlotting therapeutics, TBA has been studied extensively and has also been used for the development of TBA-electrochemical biosensors for the detection of thrombin [40, 41]. 

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