Development of a Molecularly Imprinted Polymer for Use in Biomolecule Detection

Abstract

Molecular recognition is an important area of research as it has far reaching applications in sensors, molecular separations, and medicine. Molecularly imprinted polymers offer an option for developing high resolution tools of detection that are both selective and sensitive. As a platform, carbon nanotubes offer a highly conductive surface and their growth and unique magnetic properties can be manipulated for our purposes. Such carbon-nanotube based sensors can afford high sensitivity, while molecular imprinting provides the selectivity of detection with the flexibility of fabrication. In order to fabricate a molecular imprint, monomeric compounds are polymerized in the presence of a target molecule of interest, which acts as the template. Once the template molecule has been removed an imprint capable of “recapturing” the target molecule is left behind. In this work we used cyclic voltammetry as a means of depositing polymer coatings doped with a target molecule. We fabricated a molecularly imprinted polymer sensor specific for ferritin using polyphenol as the polymer. The development of our imprint was monitored based on changes in impedance levels calculated by electrochemical impedance spectroscopy. After depositing ferritin-doped polyphenol layers we evaluated the effectiveness of different eluant solutions. Ultimately, deionized water was determined to be the developing solution of choice because it effectively removed the ferritin while not compromising the integrity of the remaining polymer coating. The sensor was capable of detecting ferritin at a concentration of 1x10-9 g/L (1 pg/mL). In parallel we evaluated the stability of the polyphenol coating.