We have investigated the capability of single-walled carbon nanotubes (SWNTs) to penetrate the cell wall and cell membrane of intact plant cells. Confocal fluorescence images revealed the cellular uptake of both SWNT/fluorescein isothiocyanate and SWNT/DNA conjugates, demonstrating that SWNTs also hold great promise as nanotransporters for walled plant cells. Moreover, the result suggested that SWNTs could deliver different cargoes into different plant cell organelles.

Cells interact with the extracellular environment through molecules expressed on the membrane. Disruption of these membrane-bound interactions (or encounters) can result in disease progression. Advances in super-resolution microscopy have allowed membrane encounters to be examined, however, these methods cannot image entire membranes and cannot provide information on the dynamic interactions between membrane-bound molecules. Here, we show a novel DNA probe that can transduce transient membrane encounter events into readable cumulative fluorescence signals. The probe, which translocates from one anchor site to another, such as motor proteins, is realized through a toehold-mediated DNA strand displacement reaction. Using this probe, we successfully monitored rapid encounter events of membrane lipid domains using flow cytometry and fluorescence microscopy. Our results show a preference for encounters within different lipid domains.