Aptamer-based sensors: Developing electrochemical and surface plasmon resonance sensors using aptamers as target recognition elements

The development of an aptamer-based electrochemical sensor focused on the synthesis and characterization of a redox-active [Co(4-(3-carboxypropyl)-4'-methyl-2,2'-bipyridine)(2,2'-bipyridine) 2]3+ complex. The cobalt bis(bipyridyl) and modified bipyridine reagents were successfully synthesized and subsequent reactions to produce the desired complex were performed. Characterization of the reaction products confirmed the successful synthesis of the cobalt complex, with the best purity being achieved using water as a solvent. Preliminary electrochemical characterization and conjugation attempts indicated that the label complex may be applicable in the desired sensor design.;A different aptamer-based sensor was created by exciting surface plasmon resonance (SPR) at the surface of a gold-plated optical using tilted fiber Bragg gratings that were written into the core of the fiber. A measureable change in the SPR was observed during the immobilization of a thiolated aptamer to the gold surface, and during the subsequent binding of the aptamer to its target. Microscopic characterization techniques were used to correlate the shift in SPR to the visual conformation of the surface immobilization of the aptamer and target binding.