Zinc-Supported Multiwalled Carbon Nanotube Nanocomposite: A Synergism to Micronutrient Release and a Smart Distributor To Promote the Growth of Onion Seeds in Arid Conditions.

In the current scenario, nanotechnological applications in the agriculture sector showing potential impacts on the improvement of plant growth in terms of protection and safety are at a very nascent stage. The present study deals with the synergistic role of zinc (Zn) and multiwalled carbon nanotubes (MWCNTs) synthesized as a zinc oxide (ZnO)/MWCNT nanocomposite, a prospective applicant to modulate the micronutrient supply and enhance the growth of onion seeds, thereby replacing harmful, unsafe chemical fertilizers. To the best of our knowledge, this is the first report wherein MWCNTs have been envisaged as a micronutrient distributor and a nutrient stabilizer enhancing the growth of onion plant under arid conditions. The growth trend of onion seeds was evaluated in an aqueous medium with varied concentrations of (i) MWCNTs, (ii) zinc oxide nanoparticles, and (iii) ZnO/MWCNT nanocomposites. ZnO/MWCNT nanocomposites with 15 µg/mL concentration displayed the best seedling growth with the maximum number of cells in telophase. A significant growth trend with increased concentration of ZnO/MWCNTs displayed no negative impact on plant growth in contrast to that with the use of MWCNTs. The synergistic impact of Zn nanoparticles and MWCNTs in ZnO/MWCNT nanocomposites on the rate of germination was explained via a mechanism supported by scanning transmission electron microscopy.

Supplementing zinc oxide nanoparticles to cryopreservation medium minimizes the freeze-thaw-induced damage to spermatozoa.

The sperm DNA integrity post cryopreservation of human semen samples is one of the serious concerns in human infertility treatment. In the present study, the beneficial effects of zinc oxide nanoparticles in preserving the functional ability of spermatozoa was explored. Ejaculates of normozoospermic men cryopreserved along with Zinc oxide nanoparticles (ZnONPs) exhibited non-significantly higher percentage of total and progressive motility in frozen-thawed samples compared to control. The sperm chromatin damage and malondialdehyde (MDA) level was significantly lower in ZnONPs group (P < 0.01 and P < 0.05 respectively) and the spermatozoa's ability to undergo acrosome reaction was also unaltered. Fluorescence microscopy and High resolution transmission electron microscopy analysis demonstrated that the ZnONPs do not penetrate the membrane of spermatozoa but stay around the spermatozoa. In conclusion, the presence of ZnONPs during cryopreservation appears to be beneficial to the spermatozoa as they withstand freeze-thaw process competently better than control, without any adverse effect shown.