Grafting of molecularly imprinted polymers on iniferter-modified carbon nanotube

Molecularly imprinted polymers (MIPs) were grafted on iniferter-modified carbon nanotube (CNT). Tween 20 was first immobilized on CNT by hydrophobic interactions. The hydroxyl-functionalized CNT was modified by silanisation with 3-chloropropyl trimethoxysilane. The iniferter groups were then introduced by reacting the CNT-bound chloropropyl groups with sodium N,N-diethyldithiocarbamate. UV light-initiated copolymerization of ethylene glycol dimethacrylate (crosslinking agent) and methacrylic acid (functional monomer) resulted in grafting of MIP on CNT for theophylline as a model template. MIPs grafted on CNT were characterized with elemental analysis, scanning electron microscopy, and thermogravimetric analysis. The theophylline-imprinted polymer on CNT showed higher binding capacity for theophylline than non-imprinted polymer on CNT and selectivity for theophylline over caffeine and theobromine (similar structure molecules). The data of theophylline and caffeine binding into the theophylline-imprinted polymer correlated well with the Scatchard plot. These MIN on CNT can potentially be applied to probe materials in biosensor system based on CNT field effect transistor. (C) 2009 Elsevier B.V. All rights reserved.