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Semiconductor nanostructures produced by wet chemical synthesis are extremely heterogeneous, which makes single particle techniques a useful way to interrogate their properties. In this paper the ultrafast dynamics of single CdTe nanowires are studied by transient absorption microscopy. The wires have lengths of several micrometers and lateral dimensions on the order of 30 nm. The transient absorption traces show very fast decays, which are assigned to charge carrier trapping into surface defects. The time constants vary for different wires due to differences in the energetics and/or density of surface trap sites. Measurements performed at the band edge compared to the near-IR give slightly different time constants, implying that the dynamics for electron and hole trapping are different. The rate of charge carrier trapping was observed to slow down at high carrier densities, which was attributed to trap-state filling. Modulations due to the fundamental and first overtone of the acoustic breathing mode were also observed in the transient absorption traces. The quality factors for these modes were similar to those measured for metal nanostructures, and indicate a complex interaction with the environment.

• ZnO nanoparticles (NPs) are administered to barley with the hydroponic culture. • When subjected to surface modification, non-toxic ZnO NPs have potential applications as biomarkers for edible crops. • Uptake ratios, r upt , are determined using electron microscopy analysis. • An r upt of 40% is obtained with arbuscular mycorrhizal fungi and fertilizer supplements and 0% without any supplements. • Arbuscular mycorrhizal fungi enhance water absorption in mutualism with the root. Nanoparticles (NPs) show great promise in developing biomarkers for specific targets such as diseases, provided their surfaces are adequately modified. Zinc oxide (ZnO) NPs, which are non-toxic, are a strong candidate for use as markers, as we have accumulated knowledge on how to chemically modify their surface. In this study, we determined the uptake ratio (r upt) of ZnO NPs in barley using electron microscopy and related techniques. When using single ZnO NPs, the r upt value was 0% at the leaf part. However, when cultivated with arbuscular mycorrhizal fungi and liquid fertilizer, r upt increased to 40%. This result may be attributed to the mutualistic relationship between the fungi and the root, which enhanced water absorption due to the more efficient activity of the rhizosphere. [ABSTRACT FROM AUTHOR]