Synthesis of Carbon Nanotube Incorporated Molecular Imprinted Polymer with Binding Affinity towards Testosterone

A novel polymer was synthesised using functionalized carbon nanotube and acrylamide as the polymer support for the separation of testosterone. The developed polymers were characterised using FT-IR, XRD, and SEM techniques. Imprinted polymer showed specificity towards the template testosterone. Among the various polymers, the MWCNT incorporated polymer showed high binding towards the used template. Investigation of the selectivity characteristics revealed that the developed polymer showed selectivity toward the template testosterone than similar compounds. The bound template could be totally recovered and regenerated polymer maintains its recognition property after repeated use. On the basis of the results, the imprinted polymer can be applied for the direct extraction of testosterone in clinical analysis. 1. Introduction Molecular imprinting has become an effective way to prepare polymer materials that show a “memory effect” toward their templates [1]. Compared to other recognition systems, MIPs possess many promising characteristics, such as low cost and easy synthesis, high stability to harsh chemical and physical conditions, and excellent reusability [2]. The molecular imprinting technique, first proposed by Wulff and Sarhan in 1972 [3], is one of the promising and facile methods to impart molecular recognition sites in synthetic polymers. Molecular imprinted polymers (MIPs) have been used for molecular recognition ranging from small molecules [4, 5] to macromolecules [6, 7]. The improper or illegal use of hormones as veterinary drugs may result in unwanted residues in food products derived from livestock breeding. However the direct detection of target corticosteroids in complex biological matrices can be a difficult task, and sample cleanup treatments are frequently necessary before performing the instrumental analysis. To extract synthetic corticosteroids from biological samples using the MIP approach efficiently, an imprinted polymer should be able to selectively recognise the main analytical target by making use of several noncovalent interactions. Multiwalled carbon nanotubes (MWNTs), which were first discovered in 1991 [8], are widely considered the quintessential nanomaterial. Due to their high strength, extremely large surface areas, and unique chemical properties, MWNTs can serve as a reinforcing element or the core when fabricating core-shell structural MIPs. A thin layer of MIPs can be polymerized onto the surfaces of MWNTs. Thus, binding cavities in the thin MIPs outer layer can greatly improve the accessibility to template molecules.