Novel Method for the Direct Visualization of in Vivo Nanomaterials and Chemical Interactions in Plants

The increasing use of nanomaterials in almost all sectors of society (e.g., health or energy to agriculture and transport) has generated a need for innovative detection methods for nanomaterials, to enable their continued development, environmental and toxicological monitoring, and risk assessment. In vivo nanoparticle visualization is needed to support applications in drug delivery to plant biology where real-time monitoring is essential. Techniques are sought that do not require the addition of molecular tags or nanotags to enhance detection, because these may modify the surface properties or behavior of the nanomaterials. Here two-photon excitation microscopy coupled with plant, nanomaterial, or chemical autofluorescence is used to detect and visualize multiwalled carbon nanotubes (MWCNTs), titanium dioxide, and cerium dioxide in living wheat tissues. The potential of the technique to track chemical−nanomaterial interactions in living tissues is then demonstrated, using phenanthrene as a model compound...