Exfoliated and water dispersible biocarbon nanotubes for enzymology applications

In this chapter, we report a simple and facile method to armor enzymes with carbon nanotubes (CNTs) which are exfoliated, and debundled using bovine serum albumin (BSA). The fabricated CNT/BSA dispersions are biofriendly, biocompatible, defect-free, and highly stable solutions. BSA gives maximum exfoliation efficiency, exceeding the 4mg/mL of CNT concentration compared to any previous reports. Further, the produced bioCNT dispersions were characterized by UV-visible, Raman, circular dichroism spectroscopy, and scanning electron microscopy (SEM). Exfoliation and debundling of the bioCNT dispersions is possible due to the π-π interaction, hydrogen bonding, hydrophobic interaction, and electrostatic attractive forces driving the adsorption of BSA on CNTs surface. Protein adsorption then makes a highly stable suspension in water that can be stored for a prolonged period. CNT dispersions are stable over a wide range of pH from 3 to 10 and at 4°C or 25°C for more than 2 months. Here, we also report the facile, inexpensive and green-chemistry method to fabricate a buckypaper (CNT paper), composed of the high packing density, self-assembled and randomly oriented bioCNTs, and these assemblies could be used in many emerging applications like air and water purification, nanocomposites, energy storage, and biosensing. Moreover, the CNT dispersions stabilized by BSA were successfully used in enzyme binding and kinetic studies and bound enzyme retained substantial catalytic activity. The current approach may facilitate bulk production of water dispersed CNTs in both academic and industrial laboratories. This is done by a simple method of stirring, which provides new opportunities for a wider range of CNT applications.