Protein functionalized carbon nanomaterials for biomedical applications

Since the discovery of low-dimensional carbon allotropes, there is increasing interest in using carbon nanomaterials for biomedical applications. Carbon nanomaterials have been utilized in the biomedical field for bioimaging, chemical sensing, targeting, delivery, therapeutics, catalysis, and energy harvesting. Each application requires tailored surface functionalization in order to take advantage of a desired property of the nanoparticles. Herein, we review the surface immobilization of bio-molecules, including proteins, peptides, and enzymes, and present the recent advances in synthesis and applications of these conjugates. The carbon scaffold and the biological moiety form a complex interface which presents a challenge for achieving efficient and robust binding while preserving biological activity. Moreover, some applications require the utilization of the protein-nanocarbon system in a complex environment that may hinder its performance or activity. We analyze different strategies to overcome these challenges when using carbon nanomaterials as protein carriers, explore various immobilization techniques along with characterization methods, and present recent demonstrations of employing these systems for biomedical applications. Finally, we consider the challenges and future directions of this field. (C) 2015 Elsevier Ltd. All rights reserved.