Effect of galvanotaxic graphene oxide on chloroplast activity: Interaction quantified with Biolayer-Interferometry coupled confocal microscopy

The knowledge on the effect of graphene oxide (GO) on plants are limited to germination, growth, and toxicity. Since, chloroplast generates sugar by the reduction of CO2 with the optical stimulation through a series of electron transport chain and GO being the 2D material with electron transport property, it is reasonable to check their interaction. Here, the effect of GO without and with amine conjugation (AGO) having opposite charges were allowed to interact with chloroplast. The uptake is documented by using biolayer interferometry coupled with confocal imaging. The ex vivo chloroplast activity with GO and AGO has been tested and found that the GO treatment shows 1.3 times more activity than control. In contrast, AGO function as efficient electron conductor and cause imbalance in the redox beyond the capacity of the antioxidant rich chloroplast solute. Finally, in vivo toxicity has been evaluated in the spinach plants, which highlights the chance of AGO application as herbicide to remove any unwanted plants.