Described herein are suspensions of helical polycarbodiimide polymers that ‘；cloak’； nanotubes, thereby effecting control over nanotube emission, providing a new mechanism of environmental responsivity, and enabling precise control over sub-cellular localization. The helical polycarbodiimide polymers described herein are water soluble, easily modifiable, and have unique architectures that facilitate their application in radiopharmaceutical delivery and imaging methods, in therapeutics and therapeutic delivery methods, and their use as sensors—；both in conjunction with carbon nanotubes, and without nanotubes.
