Carbon nanofibers as a micronutrient carrier in plants: efficient translocation and controlled release of Cu nanoparticles

An aqueous colloidal dispersion (similar to 230 nm average size) of the copper (Cu) nanoparticle (NP)-grown carbon nanofibers (CNFs) was used as a stimulant for crop yields. The Cu-CNFs (average diameter = 95 nm), separately prepared on an activated carbon microfiber substrate using chemical vapor deposition, were dispersed in Cicer arietinum seed-containing water. The CNFs served as a carrier for the Cu micronutrient, with a controlled release of the Cu NPs. The CNFs also served as a growth stimulant by increasing the water uptake capacity of the plants. The scanning electron microscopy images, elemental (Cu/C) mapping, and atomic absorption spectrometry data corroborated the effective translocation of the Cu-CNFs from the root to the shoot of the plants. The water uptake capacity, germination rate, shoot and root lengths, and chlorophyll and protein contents significantly increased in the plants using the Cu-CNFs. This is the first study showing the use of the Cu-CNFs as a carrier of micronutrients in plants, with an effective translocation ability.