Nanosensors, particularly those based on nanoparticle transducers, have demonstrated the ability to detect the binding of molecules at the single analyte level. Our lab at MIT has been interested in how the nanoparticle corona – the region of adsorbed molecules surrounding the particle surface can be engineered for molecular recognition. We have recently introduced a method we call CoPhMoRe, or Corona Phase Molecular Recognition for discovering synthetic, heteropolymer corona phases that form molecular recognition sites at the nanoparticle interface, selected from a heteropolymer library. We show that certain synthetic heteropolymers, once constrained onto a single-walled carbon nanotube by chemical adsorption, also form a new corona phase that exhibits highly selective recognition for specific molecules. We have a growing list of biomolecules that we can detect using this approach, including riboflavin, L-thyroxine, dopamine, nitric oxide, sugar alcohols, and estradiol, as well as proteins such as fibrinogen. The results have significant potential in light of the fact that nanoparticles such as single-walled carbon nanotubes can be interfaced to biological systems at the subcellular level, with unprecedented sensitivity. Several recent demonstrations indicate that spatial and temporal information on cellular chemical signaling can be obtained using arrays of such sensors. Other examples, including sensor tattoos for mice, that are stable for more than 400 days in-vivo, will be shown. Lastly, I will highlight recent advances to control the tracking and localization of nanoparticle systems in living plants using a mechanism that we call Lipid Exchange Envelope Penetration (LEEP). We demonstrate a living plant, interfaced with multiple nanoparticle types that can detect explosives, ATP, and dopamine within or from outside the plant, and communicate this information to a user’s cell phone. Engineering the nanoparticle corona in this way offers significant potential to translate sensor technology to previously inaccessible environments.
