Indoor Floating Dust Contains Graphene Derivative to Generate Reactive Oxygen Species with Visible Light and Oxygen

Abstract This work reports the analysis of black dust deposited in the filters of AC machines and black dust deposited on ventilator or fan blades in indoor offices. The protocol we have developed has been followed in extracting yellow solution from the purified black dust using aqueous alkaline medium. This under acidification and digestion yielded blackish–brown precipitate which on spectroscopic, microscopic and XRD studies show the presence of reduced graphene oxide (rGO) along with graphene oxide (GO). It has been shown that such dust is toxic due to the presence of rGO. This form of graphene readily releases electron even under visible light which is capable to generate super oxide radical anion (O2-1) (the first ingredient of reactive oxygen species, ROS) in contact with aerial oxygen. The superoxide generation by the purified dust is confirmed by nitro bluetetrazolium chloride (NBT) test in the presence of light and oxygen. The inter conversion process between GO and rGO in this reaction has been investigated.