Synthesis, Surface Modification and Environmental Impact of InSe 2D Nanomaterials

Semiconductor InSe 2D nanomaterials are interesting materials for photodetectors and wearable electronics due to their high photoresponsivity and thermal stability. The chemically synthesized InSe nanomaterials can be formed in different crystalline phases (α, β, γ) and oxidation states depending on their reaction conditions, resulting into forming materials with different lattice constants and bandgap values. Usage of InSe and similar 2D nanomaterials is expected to grow exponentially in the next decade. However, their unique morphology and ability to produce reactive oxygen species (ROS) could adversely affect human health and the environment. There is an urgent need to address these environmental concerns before the expected growth of their use. Our studies aim to increase molecular level understanding of the impact of surface modified InSe 2D nanomaterial on its stability and interactions with model membranes and biological organisms relevant to human health and the environment. InSe 2D nanomaterials are formed using a semi bottom-up hot injection method. The reaction conditions such as the reaction time and temperature are tuned to obtain either 2D nanoflakes or nanoparticles of InSe. The as-formed InSe 2D nanoflakes and nanoparticles are hydrophobic and thus insoluble in water. However, biological studies relevant to human health and the environment with these materials require them to be soluble in water. The InSe nanostructures are hence coated with amphiphilic natural organic matter (NOM) simulant like epigallocatechin gallate (EGCG), and different surfactants of varying surface charges to render them soluble in aqueous media by surface modifications via physisorption. The presentation will demonstrate our detailed structural, optical, and morphological analyses of as-synthesized as well as the modified InSe nanomaterials and the use of fluorescence spectroscopic techniques for quantitative determination of the interactions and impact of InSe 2D nanoflakes and nanoparticles on phospholipid vesicles lysis and the viability of bacterial cells.