Ultrasensitive detection of biomolecules using functionalized multi-walled carbon nanotubes

An ultrasensitive and facile bioassay approach is developed using biofunctional multi-walled carbon nanotubes (MWNTs). The biofunctional MWNTs are exploited to detect trace protein in the homogeneous solution using fluorescent detection. The effect of target concentration on the fluorescent intensity is systematically studied, revealing that the detected signal is strengthened with increase in target concentration. The homogenous target-capture process performed on the biofunctional MWNTs enhances the detection sensitivity largely. The detection limit of 100 pg/ml is achieved through this bioassay. (c) 2007 Elsevier B.V. All rights reserved.