Journal Article 7782-42-5 Graphite graphene Antibodies, Viral Ligands Opsins Research Support, Non-U.S. Gov't artificial biomaterials biological mimicking color sensitivity field-effect transistors flexible electronics human opsin proteins immunoassay interfacing chemistry microfluidics nano-biohybrids neural networks photoreceptors photosensitive cells portable devices receptonics respiratory viruses spectral characteristics spheroids